Plants with Attitude
A brief overview of general requirements for Nepenthes cultivation. 
Temperature
It is now widely known that, insofar as cultivation is concerned, Nepenthes may be classified as lowland (growing at or below 1000 m elevation) or highland (growing above 1000 m elevation).  The principle distinction with which the grower must be concerned is the marked difference between nocturnal temperatures which these two groups experience.  In general, lowland plants require temperatures between 20 and 35 C.  They may therefore be grown fairly easily in the home, or in a well heated greenhouse.  Highland Nepenthes, however, are more demanding since, virtually without exception, they require warm days and rather cool nights.  An acceptable temperature range is roughly 10 to 30 C.  Failure to heed this requirement will likely lead to the death of these plants, and it is therefore recommended that one avoid highland plants unless able to address this need.
Humidity
Humidity is a must.  If one does not reside in an area with high levels of natural humidity, it will be necessary either to purchase a humidifier, or to grow one's plants in tanks containing some amount of water.  We recommend ultrasonic humidifiers, which work quite well -- provided that they are kept clean to prevent the possible buildup of microbes in the water reservoir, a condition quite dangerous.
Illumination
Nepenthes can be grown successfully using a number of different sources of illumination.  Possibilities include common fluorescent lamps, metal halide grow lamps, or filtered sunlight.  If you elect to use fluorescent lamps, be sure to replace the bulbs every six months or so to ensure adequate illumination.  The output of biologically useful light from them declines substantially after several  months, and your plants will suffer from this if bulbs are not replaced accordingly.  We also recommend the use of a timer to provide a regular photoperiod.  Approximately twelve hours of light per day is adequate to ensure rapid growth.  Illumination for longer periods of time can burn the leaves of many species of Nepenthes.  Metal halide lamps are a good source of light for larger growing areas, or to supplement natural light during the darker months of winter.  However, such equipment can be costly.  Finally, if you simply rely on sunlight, be sure that your plants are adequately ventilated to ensure that they don't overheat, especially if they are highland plants.
Feeding/Fertilization
We do not, as a rule, fertilize Nepenthes.  Since these plants have evolved a means of extracting nutrients from their environment which does not rely upon absorption through roots, it is our opinion that the best way to grow them is to feed with insects.  This may be accomplished by buying crickets from your local pet store, or via e-commerce.  Crickets may be stored for long periods by freezing them, and may then be rapidly thawed out for feeding.  Based upon a number of years of growing experience, we believe that this is the single best way to obtain large plants in rapid fashion.
Watering
Being rainforest plants, Nepenthes must be kept moist.  With a few exceptions, most should not be permitted to sit in water, but should be watered every day, or every few days. Ours are refreshed with water purified by a reverse osmosis unit, available commercially at most home improvement centers for roughly $200.  The use of purified water prevents the buildup of mineral salts in the compost, a condition which is detrimental to most Nepenthes.  Furthermore, water so purified is also far more palatable than the chlorinated slop coming directly from one's tap!
Compost
Having not as yet had the pleasure of observing Nepenthes in habitat, we cannot comment directly upon their natural compost.  However, we have had success with a number of compost blends composed of materials commonly available.  Typically, a mix consisting of sphagnum peat moss, fine horticultural charcoal, and fine orchid bark, in the approximate ratio 1:1:1, is used.  However, those species growing in swampier areas, e.g., N. mirabilis, generally fare well in a mixture with more peat than anything else, while a number of the highland plants, such as N. rajah, seem to prefer a more coarse, well drained mixture, consisting of less peat, and possibly including other components, such as pumice.
Cultivation Difficulty
Nepenthes may generally be successfully cultivated by anyone, provided that one meets their basic needs.  However, such needs vary greatly from one species to another, and for some species, they may be rather challenging to meet.  Of course, what may be difficult for one grower to provide may be quite easily offered by another.  Nonetheless, it is possible to offer some general guidelines based upon personal experience, consultation with other growers, and basic awareness of the tools and methods commonly used to cultivate exotic flora in general.

Therefore, in the interest of providing some broad guidelines for those new to Nepenthes cultivation, or for those who may be considering a new and potentially difficult species, our personal estimation of cultivation difficulty for each species presented on this site is given according to the scheme below.  Such assessment is reasonably subjective, and is intended only as a guideline.  Obviously, given the unique set of conditions you provide, or even possibly due to a unique clone you may have, your experience could differ greatly from ours. 

Difficulty Classification Scheme
1. Easy Most lowland Nepenthes are considered easy, as are many intermediates which generally have a reasonable tolerance for warm nighttime temperatures.  Such plants are usually fairly rapid growers which need little more than warm temperatures, approximately fifty percent shade, 60 to 70 percent relative humidity, and frequent watering with reasonably pure water.  Most are commonly available, and are therefore good choices for the beginner. Of course, if you live in a rather cool climate, you may find such plants to be far more difficult than someone living in a warm or temperate country.  Nonetheless, because it is usually easier to provide heat than to remove it, most lowland plants are considered fairly easy.
2. Moderate Many Nepenthes considered intermediate growers (those growing from about 900 m to 1400 m elevation) fall into this category.  Such plants typically require some degree of nocturnal cooling (usually below 20 C).  Therefore, for those living in tropical or subtropical locations, such plants should only be cultivated if such cooling is provided.  In addition, plants in this category are often more slow-growing than those in category 1.
3. Challenging These plants should probably only be grown by those who have reasonable experience growing Nepenthes, and who are well aware of, and capable of providing for, their needs.  Such species are typically true highland plants, and are therefore absolutely in need of substantial nighttime cooling, or other specific conditions or composts.
4. Difficult Nepenthes in this category are few in number, but are notoriously difficult because of the very specific conditions they require, and because such conditions are difficult for most growers to provide.  Moreover, they are often quite slow-growing and are a poor choice for most younger growers or those who are not yet settled enough to provide the plants with a stable growing environment for the long term.  Therefore, these plants are only recommended for those with considerable experience, patience, and genuine devotion.
One final point to consider regarding the matter of cultivation difficulty is that many species, particularly highland species from tissue culture, are much more tolerant of overly warm conditions when small than they will be as they mature.  It is therefore probably wise to plan for and provide the cooling they will need as adult plants.
Propagation
Nepenthes may be propagated by a number of different means, including modern tissue culture techniques.  However, for most growers the most popular method of propagation simply involves taking cuttings.  Cuttings should be taken from healthy plants which have one or more developed shoots in addition to the one to be used for propagation.  Listed below is a step-by-step procedure for this method of propagation.
1. Simply remove the desired plant material and cut it into sections, allowing two or three nodes per section.  If healthy pitchers are present on leaves, they may be left on and filled with water to act as a reservoir; this can help cuttings to stay hydrated.  However, if healthy pitchers are not present, it is usually advisable to cut leaves in half to limit transpiration and the stress it places on new cuttings.
2. Trim each section with a very sharp knife to ensure that the vascular bundles inside the stem are not crushed and remain viable; it is also useful to perform this task under water to prevent the formation of an air embolism at the site of the cut.  Furthermore, make the cut at a very oblique angle to allow for maximum surface area at this end of the cutting; this will allow better hydration of the cutting.
3. Make three or four longitudinal incisions approximately 2 mm deep and about 2 cm long at the base of the cutting.  In a few weeks, these incisions will split open, and somewhat later, roots will grow out of these areas.
4. Treat the root ends of the cuttings with a rooting hormone.  Such treatment usually increases the percentage of cuttings which successfully root.
5. Place the root ends of the cuttings in moist sphagnum, or a similar substance, and locate them in an area with conditions similar to those favored by the plant from whch they were taken.  However, be sure that humidity is high and that temperatures do not climb to too high a value, lest the new cuttings wilt and die.  In a few weeks to a few months, roots should appear on the cuttings; when these roots are several centimeters in length, the cuttings may be removed from the moss (taking care not to break the fragile, new roots) and planted in regular compost.
For further information regarding Nepenthes cultivation or habitats, or to find sources for Nepenthes, please peruse our list of  references and links.