Hi there boots. Try searching for rack threads for ideas. You need to find your own level when it comes to neatness. Personally, I'm a neat freak when it comes to wiring, but age & experience has taught me that to much time can be wasted on that sort of thing. If it is fairly permanent, I'll take the time to make it near perfect, but I know my rack will change from time to time.
So my level of analness (is that a word?) is to have my cabling quite neat and easy to follow, but still be easy to move cables & components without a major overhaul. I don't build custom length interconnects cause if anything at all changes then I gotta toss the cables & build new ones. I just buy whatever is close and dress the cables to keep them reasonably neat. See the photo for an idea of what I mean. Not super clean, but it's easy to trace cables & change things up if needed.
Do not judge me by the mess in the room. Things were being rearranged at the time.
For room wiring, a couple of things. Get cable that is approved for use within walls. There are smoke & flame spread ratings that should be paid attention to. Keep audio/video cables separated from the 120 VAC house wiring to minimize interference & noise. Crossing over those cables is fine, but you don't want to run the audio & 120 cables right together for long distances. If you keep them 6" apart, they'll be fine.
What you can't see in the pic is that I have a mill work boarder around perimeter of the room that's dropped about 6" from the ceiling & 18' wide. It has removable panels that made it a breeze to run speaker & network cables. All the speakers run down to a 3 gang box in the wall behind the rack with a cover plate chock full of banana plugs.
Each device that is network connected gets a CAT6 drop; TV, AVP, Blu-Ray, Apple TV, and HTPC, plus a spare. No wireless connections cause they can be an endless source of frustration when they don't work perfectly. No TV cable coax either cause it's almost obsolete. Everything is either streamed, Blu-Ray, or from a Plex server in another room.
Power is a 120V, 30A receptacle behind the rack. This powers a gang of receptacles in the rack that are each protected by a 15A mini-breaker. This provides power for all the AV equipment. With separate circuits there can be an increased possibility of introduced ground loop hum with different components connected to different circuits. Unlikely, but they can be a bugger to track down & get rid of (properly).
Hope this helps & good luck. Have fun with this.