The real problem with A/V is there is no standard. It's almost a joke with how little there is in the way of any standard. You get companies which produce a beautiful product like the Nest thermostat... Then they completely hide the Ethernet control protocols so that there is no way for any control system to talk to them to just get the current temperature of the house, let alone bump the temperature up or down a few degrees. One company will do things one way, and another company will do things another way.
Certainly, there are companies you can go to which provide a great deal of automation products. Crestron, AMX, Control4, etc. are all automation companies, but they generally have higher than typical price tags, they are not (generally speaking) end-user installed or programmed. They may provide some decent products, or some excellent products, but quite often, you want to buy the 'best' product, and that will come from a different company altogether, so then you must build that interface.
Eventually, you start thinking more about finding a control solution to every system in your home as you want it. Fireplaces are generally low-voltage relay controlled at the basic level, but perhaps you want something more. HVAC has a few control options out there which are decent... But, how often do you want to change your thermostat and do you need something integrated, or is a stand alone application like Nest offers sufficient? Same with your home security. Lighting can get very expensive, but certainly is one of those 'most desired' control options that I hear about.
But, it is cat-6 cabling which really can do a lot of different functions for control. It can carry some low-voltage power, it can carry control signals, it can carry Ethernet, audio, video... Kind of a long list of things it can do pretty well.
Speakers, on the other hand, should all be wired, and they should all have a decent speaker wire run to them.
Plan on your equipment location (head end) and make sure it is large enough to handle all the gear you want to put into it. That's where your cable TV system should go, where your security should go, where your phone, and Ethernet should go. Generally speaking, whatever space you allocate will probably not be enough. So, that's when you go back to your planning.
For your consideration: I have two 6' tall equipment racks in my basement and they are almost completely filled. I am starting to make some other considerations for where I will be putting more equipment in the future. More likely, I will relocate some networked items to a different spot. Still, the space does fill up.
So, that's why you start with the first step.
Figure out what it is you want, and then start planning for it.
The FAQs are nice, but probably won't give you enough information for your specific setup, but some basics can certainly start you on your way. Before you pull the first wire, and well before the first studs are in place, you should be asking questions and putting together a serious wire-pull list for your home. Consider conduit, and other access for the future as well.