I need a new storage unit for a very very tiny closet. Could you help me find something to maximize my tiny space?

Target, Walmart and the Container Store all have many closet organizing options.

Depending on how you will organize your closet I recommend that you purchase a tension rod from any curtain store and make an extra hanging space in your small closet.  Then I'd get one or more of the items below, over the door shoe storage saves a lot of space, there's also a shoe cubbie if you prefer to store your shoes and other items on the floor.  Keep in mind you can roll accessories and store them in the shoe cubbies as well.  Next I'd set up storage cubes or totes, which ever fit and make a place for all of your clothing, shoes and accessories.  I hope you found this helpful!

I'd also get a set of wonder hangers as described below.
http://www.shopgetorganized.com/item/wonder_hanger_8_pack/29749
Wonder Hanger™ eight pack triples closet storage space by allowing you to hang up to five articles of clothing wrinkle-free on a single hanger. The easy "on and off" design allows each hanger to rest on a closet rod horizontally or drop down vertically to maximize storage and free up space. Won't bend or sag - strong enough to hold five winter coats! Ideal for apartments, dorms and older houses with limited closet space. Organize clothes, belts, purses and accessories too. Polypropylene, 9 3/4 x 1 x 1/4". Set of eight.