There are a few basic needs all reptiles have. Food, water and heat are the first three. I'm just going to talk about these in this blog post and I'll talk about more advanced needs in another.
There is a wide variety of diets for reptiles from herbivore to carnivores to omnivores to insectivores. Depending on which one your reptile is there are a variety of prepared diets for them. For example bearded dragons eat just about anything they can fit in their mouths. They like dragon pellets as well as freeze dried crickets or meal worms. They'll also eat fresh fruit, veggies and lettuces. I give mine all of these and sometimes pinkies or live crickets, meal worms or cockroaches as a treat. The best thing to do is read a book about the reptile you have or are going to get to find out what is the best for him or her.
Everything needs water of coarse but depending on what kind of reptile you have will determine how much. Some species of desert reptile will get all their water from the food they eat. It still is a good idea to keep fresh water in with your reptile just in case it gets thirsty. I will soak mine weekly so they can drink and get dirt and shed off. Some turtles and amphibians will need to be able to completely submerge themselves but will also need to be able to dry completely when they want to. It's good to have a basking light on one end where your pet will be able to climb out of the water and get close to.
Which brings me to my next topic of heat. There are many different ways of heating a cage. The easiest of course is a basking light as I mentioned before. Under tank heaters, Heat tape, aquarium heaters are also good sources. It's best if your reptile can get in and out of the heated side of the terrarium so he or she can thermoregulate.
Bearded Dragon Care Sheet
http://beardeddragonbreeders.blogspot.com/