In addition to the Wind-Sun site Icarus has a link to above the associated forum he has provided a link to below, I found the following sites helpful in designing and building the electrical system in my conversion.
http://handybobsolar.wordpress.com/. Lots of practical information about RV solar installations, wiring, and batteries from an electrical engineer who has been boondocking for 7 plus years without resorting to a generator and rarely having to plug in. He lambasts RV dealers and RV solar "experts". Well worth reading his blog.
http://www.vonwentzel.net/Battery/index.html. Lots of information about batteries from a marine standpoint. The author works through some of the myths and misinformation that abounds concerning batteries, battery types, and their use.
http://www.cruisersforum.com/forums/f14/. Link to the Batteries, Generator and Solar forum on Cruisers Forum. The information is geared to marine systems and sailing in particular but applies directly to RV systems as well. These folks' lives depend on their systems functioning properly and safely. Lots of information available using the search function.
http://www.amplepower.com/index.html Like Handy Bob these folks are iconoclasts. They manufacture and sell electrical system components and controls for marine electrical systems as well as land based solar PV systems. Click on the Technical Documents tab to get started. I ended up ordering their Ample Power CD which contains two books,
Living On 12 Volts with Ample Power and
Wiring 12 Volts for Ample Power.
Curt