When I first moved into this current house about 2 and a half years ago, I wanted to network everything. I got a 1000ft box of cable from home depot, as well as a whole bunch of wall plates. I also got a 24 port patch panel off ebay. I wired 14 runs throughout my house, more or less 1-2 to each room covering three floors. At the time I had an unfinished basement, which made things really easy. All runs on the top floor were put in the walls, where they then ran up into the attic, then ran down through a wall into a small cupboard at the top of my stairs to terminate. Main floor runs were put into the wall, then fished down into the basement where they were ran through the rafters and up into a cold air return vent which went all the way to the top floor. From there, they kept going though the wall into the attic. Basement was done the same way, running it through the cold air return once it was studded.
The job looks really professional as all the connections are in-wall, no visible wires. The entire project cost be probably $200cad since I did all the work myself.
If you want to do it yourself, try to figure out the easiest way to run wires in the first place. Drop-down celings in basements are great as well as attics. For the most part, to run lines from basements to 2nd floors, the easiest way seems to be cold air returns, but from what I'm reading, some people don't like that. Running cables through heat registers is not a very good idea. Although I have seen it done, I wouldn't suggest it. Outside runs can work if you have the proper cable, but if you do go that route, pick places that aren't really visible.
Make sure you pick a good spot to terminate the cables. Somewhere that's centralized to limit cable runs, but that's also out of the way. I've seen people terminate near the breaker box of a house. That's not a bad idea as it keeps all utilities like power, phone, internet, and cable together. Personally I'm not too big of a fan of running network cable really close to power lines so I usually chose to put them somewhere else, but that's just me. In my house, there jsut happened to be a built-in cabinet at the top of the stairs on the top floor. It made an ideal place, as it was a dead space for anything else, and was right between my room, and one of our offices, the two main rooms needing connections.
I hope this helps. Installing a network can be really cheap if you do it yourself. I think that wireless is not a very good choice for networking. Agreed, it is easier, but It's also slower, can be less secure, and will cost you more in hardware than a DIY cable install. Plus, you can't say that your house is fully networked
