First off, good deal that you decided to go wired! Wired is THE way to go. I myself have a 24 port switch, and all of my tv's and a couple towers are hardwired. I think you need to get a switch and that way you can have multiple ethernet drops. If your gonna do it go whole hog. At the bare minimum use the switch outputs to feed your office and then some Ubiquiti AP's, these will dramatically improve your wifi! In general running cable in your attic is not to bad, your just need to picture how the halls are built. You can usually see the top plates from the attic and drill thru it with your cordless. Try to make your drops on interior walls, exterior walls are difficult to drill the top plate (especially on low pitch roofs) and they will have insulation which is much more difficult to fish. If you have to fish a wall with insulation, use a fish with the end cut off. This will allow it to shot thru the insulation, you then have a helper tape a pull string to it from your box cut out. Pull the string up, and use it to pull your wire down. If I have to use a string, always leave some string in the wall for future!
There are lots of tricks, for running wire. Bendable drill bits, these lets you drill from the room thru the cut out and into the top plate. Make sure and use a good dust mask, and a head mounted light. If you have the old rock wool insulation, cover up! I new a guy that would put panty hose on his arms, it stops the fibers from getting to you.
If this sounds too difficult, you might contact a alarm installer. These guys are some of best at getting wiring to any part of a house!
P.S. I love these cat connectors!
Platinum Tools 1 C EZ-RJ45 Cat 6+ Connectors, Clamshell, 5 -Pieces - Crimpers - Amazon.com
Dave