A lot of people love the Mac for one simple reason: you can easily and quickly do amazing things on it. Once you're comfortable with your way around the Mac, it's a breeze to do all the other stuff that you haven't done before, or on things added with the release of each new version of the OS X and iOS. For most things on the Mac, you don't necessarily need a manual. You can just wing it.
However, if you want to really dig deep in order to take advantage of all the stuff you need to know and make the most out of it, you always have the option of learning its ins-and-outs with readily-available solid guides from the experts.
And on the new Photos for Mac, you've got 2 excellent choices:
First, there's one place online where you can learn all that you need to learn about the new Photos for Mac OS X, from the basic to the advanced: go to iMore. Their compilation of articles featuring many excellent tips, hints and tricks is a very deep resource on all the stuff about Photos for Mac OS X that will turn you into an expert in no time, all on one weekend even.
Second, for a very little investment (the price of a latte, as they say) that is sure to pay off in a big way, there is Jason Snell's excellent ebook from TidBITS, Photos for Mac: A Take Control Crash Course. The current ebook version is 30-page long, but will balloon to twice that many pages soon enough with a free update next month, containing all the detailed and useful stuff you need to know. If there's one person that I trust to teach me about the Photos for Mac OS X, it will have to be Jason Snell.
So, go ahead, carve out some time this weekend for a little bit of learning. It's going to be worth it.