You would be better off just buying a set of speakers because it is an easy way to get into speaker-listening, and modifying if that interests you.
Between this thread and the last couple many very nice speaker projects have been offered, and many reasons that you cant build any have been returned. If you want speakers you should get them, they are fun!
As an idea for an inexpensive starter pair: Wait for the best buy/insgnia 6.5" coaxial speakers to go on sale for $60 or so Link, and buy a set. They are fun to tweak on and not too expensive to buy even at full MSRP. You dont have to do any woodwork, they look decent, and sound pretty nice once you work on them a bit. They are durable enough, and small enough that taking them off to school with you in a few years wont be a terrible inconvenience and if they get destroyed at school who cares? You had barely $100 in the whole project and by that time you can build something bigger and better anyways.
Another GREAT source for speakers on the cheap is the local thrift store. Hit them up every week or so and read up on vintage speaker sites to familarize yourself with older speakers until you find something a tthe thrift store that interests you for pennies on the dollar. Find the foam-kits for the woofers and mids (If you even need to do that) and rock out for a good long time.
