just go down to ur local hardware store, if your still in the vegative state buy anything high in nitrogen. Seaweed based fertilizers work very well, and your best off with a liquid fert so u can just add it into the water once every 2 weeks (or whatever the bottle says) its much easier that way
There are lots of brands to choose from. Decide whether you want to go organic or not, then go from there. Take a look at what's available in your budget and go with whatever seems the least complicated. Here's a link to familiarize yourself with some of the brands: http://www.htgsupply.com/nutrientsubcategories.asp?categoryID=2