Lots of info here, at IRV2.com, etc. If you have DIY skills and understand 12v wiring, it's not difficult. Many sources sell kits complete with panels, controller, etc. 200w is a good starting point, but make sure your controller can handle expansion. If you have a residential fridge, it's a different ball game. There are a number of sites that will help you calculate your daily needs and size your system.
Home Depot has a good selection of panels and kits on line.
My advice is to keep it simple and don't obsess over every variable or you'll either never get it done or spend too much.
And don't skimp on wire gauge. There are online calculators for this as well.
2002 Itasca Suncruiser 35U