The best recommendation I can give you is to find a copy of the 2012 guide to literary agents. It's kind of expensive, but they do have it at libraries. It's a great resource if you're unfamiliar with the publishing process. But, any short work that you have, start submitting it now. Find magazines that publish your genre and send off what ever fits. For the longer pieces, start brushing up on query letters and a synopsis. The guide will help you with the basics of writing these and it will also provide a list of agents at the end for each genre.