Venus flytraps (Dionaea) generally love waterlogged conditions. They grow in marshes and bogs, so they prefer their soil to be damp at all times. The most effective way to achieve this is by keeping potted flytraps in a tray or dish of water.
They also require water that is very low in salt and other minerals. For this reason, we recommend distilled, rain, or reverse osmosis water.
Venus flytraps require intense, direct light. Most of the time this means full outdoor sun for at least 6 hours per day. Flytraps grown in windowsills usually weaken and die over time. Light is the most important thing for flytraps.
Never use commercial potting soils for Venus flytraps. These often contain fertilizers or other minerals and are dangerous for your plants. Use either a mix based on long-fiber Sphagnum moss (which we include with the plants we sell), or one based on fertilizer-free Sphagnum peat. We have more information (and also sell pre-mixed soils) in the "supplies" section. Most carnivorous plants can be repotted every 2-3 years.
Venus flytraps (Dionaea) are from the Southeastern United States, so they are very resilient to high temperatures during their growing season as long as their soil is always wet. During winter, they can easily tolerate light frost and snow.