Your best starting point is
www.gotwind.org - on this site Ben shows you how to make your own turbines from virtually waste items - hard drive motors (bound to be plenty of old PC equipment at school) and various other things. He also has a template which allows you to easily make a twin-blade from a section of old downpipe (or if that doesn't appeal to you, use some new pipe) - have a look. It's very easy and very nifty.
If you have turbines of the same voltage all you need to do is rectify the AC outputs and run the DC current direct to one battery bank.