You will need a heater 200w should be enough, there are some titanium heaters that work better than glass heaters because you avoid the risk of the glass braking.
A thermometer to keep an eye on your water's temperature
A filtration system: I'll leave you some links so you can get more familiar with the different types of filtration abailable:
Filter (aquarium) - Wikipedia, the free encyclopedia
What Does My Filter Do? - The First Tank Guide - Filtering Your Aquarium Water
Fluorescent lights will probably work best for a freshwater set up
I don't know if I'm forgetting about something but I think that's the basic stuff. Then, you will need something to remove choline and chloramine from your tap water. There's some very cheap water purifiers that work well. Last but not least, when you have your substrate, decorations, and all the above in place you can start your cycle. There's different ways to make the cycle. The people from your LFS
will probably tell you that putting some hardy fish in your tank is the best way to do it, in my opinion, it is not the most humane way of doing it. I recommend fishless cycling, do a Google search for "Fishless Cycle" there's tons of info on the Web.
Any opinions from other users?