In this video, I show you how to hook up a cheap solar panel to the batteries in an RV to trickle charge them.
Carefully consider the types of solar panels you plan on having installed. Long ago, if you didn't have enough roof space, you'd need very expensive high efficiency mono-crystalline panels. There are now more advanced polycrystalline panels and even thin film panels. If you've got enough roof space, you might wish to look at the size of the panels in relation to their output capacity to avoid having insufficient panels that you need more of later.
Remember that solar energy can do more than just power your lights. They can provide heat and warm up your water, too. Solar panels can make a significant impact in your overall energy bill. You don't want to be overpaying the power company.