I'd start with furniture and accessories to practice making the shapes I wanted, personally. once I mastered the different tools, then I tried making clothes and more complicated models.
Check out Builder's Brewery if you do better with a lil assistance, they offer FREE classes on Blender and the cycle isn't too long. It is an awesome community for asking questions in/helping others, too!
following along wiht the how tos on CGCookies, Il lbe doing the Coffe cup tomorrow and hopefully the one after that (Forget what it is atm) Im going to check out builders brewery now too