I agree to run Cat 6. Cat 5e will work but I promise you, you only want to pull cable through your house
once. So to ensure the best performance for as long into the future as possible, put in at least top quality Cat 6. You do not need conduit. Network cables uses "twisted" pairs to cancel out any affects of interference.
Do "invest" in a top quality crimper and use only top quality connectors. Practice crimping on scrap pieces of wires. Be ready to waste several connectors. I wasted $40 on two cheap crimpers before buying the quality $40 crimper I should have bought in the first place.
"Invest" also in a decent
network cable tester. The $10 testers that look identical to the $40 testers are not identical, or equal.
You are only as good as your tools. Remember, you want this wiring job to last a lifetime. It will cost you to do it right, but you will still save $100s by doing it yourself.
Leave at least a couple feet of slack at every outlet.
At least two outlets in every room. You may think one is enough, and it most likely is (since you can always put a switch in the room). But Murphey's Law will always put the outlet on the wrong side of the room from the computer. Plus, remember TVs, Roku streamers, Blu-Ray players and other devices often are able to connect via Ethernet too - always better than wireless (in terms of security).
Make sure all bends around corners are gentle curves. Do not actually bend and never allow any kinks in the cables.
Do not yank or stretch cables. If it gets hung up while pulling, crawl in or punch a hole in the wall to carefully free the hang up. If not possible, abandon the cable in place and start a new run. Do not yank or stretch the cable (worth repeating).
No splices.
Use a good router.