Instead of a manual I'd suggest manual labor. Seriously, working as an apprentice to an existing installer helps you learn a lot quickly. My other recommendation, since PV is modular, is to start small and work upward in complexity. If you do your own system first, growing it as you need to, your errors are your responsibility alone and you learn bunches from them. After almost 30 years of working with PV and wind systems I learn the most by diagnosing other installers errors, getting called by local electrical contractors and homeowners with problem systems.
A lot of his focus is on interpreting best practices and keeping things in step with the NEC (National Electrical Code). I have probably learned more from him than any one other person or source. There has been a constant evolution of the NEC and PV systems, it might be a good idea to start with the older articles and read forward. The only problem with that are the changes. It does let one see the evolution though and Wiles tries to explain the reasoning behind some of the rules.
It helps to not assume anything when thinking about PV system. DC power is different enough from AC that many parts such as common household wall switches can not be used for DC switching. Ditto for fuses and breakers in most cases. Some things are counter to standard auto practice; cars use black for negative wires for example. The NEC does not permit negative DC wires to be anything but white, same as the neutral wire in the AC circuit. I believe it is important to follow NEC practice; my reason is that if at some time an electrician, stranger to your system, has to be called in for some reason, he will be safer and may not take as much time to ascertain and repair the problem.
I've also seen a number of websites showing how easy it is to "get into" PV power. Beware of many that really want to sell you something above all else. Also beware of those who advocate slapping a couple RV batteries under the porch, panels on the porch roof and have wiring running here and there over wall surfaces ending in tangles of wires. Messy looking in other words. Unless that is what you want, then disregard most of what I say.
I have my own independent powered cabin and have some grid tied panels on our home. I don't know everything, I am not licensed to practice the trade, but am willing to help to the extent of my knowledge and opinions.
There are PV products that have the inverters built into the panels themselves. This means for installation you are working with conventional AC which is more familiar to your average electrician than the DC. The manufacturer has taken care of all of the DC code provisions in the product itself.