Let us know what your light level is, what your water chemistry is like, and how fleixble you are. Invariably the first problem is "not enough light"!!! You really will want 2 Watts of full spectrum fluorescent light per gallon as long as it is a regular shaped tank, more if it is deep or especially a hex. This will give you "Medium" light.
Here is a link to Tropica browse their plants list and see what plants match your water params and light availibility. If you go for "Easy" or "Very Easy" plants, you'll not have to worry about CO2 and the like.
where is the best place online to buy plants?
I have been into tropical fish since I was 8 years old. My first fish bowl was a 3 gallon with a black moore. I eventually moved on up over the years. I am interested in making a "natural look" aqaurium with guppies and neon/cardinal/glowlight tetras and Corydoras, they are to me the most colorful and pretty fish.(Although cichlads are cool too) what plants do you guys/gals recomend that will flourish in a comminity setting?