I get my plants at my LFS. PetSmart's plants typically look like poo, unless they just got their shipment in.
As for what plants to get, and what equipment you'll need, you're going to have to decide what type of plants you want...low, medium or high light plants. There is a thread stickied at the top of this forum called "
General Guide To Low-Light Planted Tanks". Its chock full of good information for low light plants, and a small insight to higher requirement plants as well. Also, go to plantgeek.net They have a HUGE database of aquatic plants, and it can be sorted according to plant type, placement, light requirement, difficulty, family, genus, region or category...any how, its an awesome place.
All in all, do some further research into the basics of plants, and decide how much time and money you're willing to invest, then you can probably get some more straight forward answers out of people.
P.S. you won't regret going planted
