Robert,
There is alot to it but it can be fun and you can save alot of money doing it yourself. The links the others have posted are good. I built mine along with tower speakers. You can see a pic at
www.gulfcoastwakeboarding.com page 2 - posting picture thread - Debs Dream
Yesterday I moved the speakers to the top of the tower to make room for a bimini we plan to get over the winter. After reading the above attachments - if you still have questions - just ask here or e-mail me direct.
Scott