Without any particular expertise and with advice from the sales staff at a good computer store, I wired my own home with Ethernet cable. Running wire may seem daunting, but if the path is relatively clear, it is not hard. The pro's really earn their money when it requires specialized study and experience to overcome significant problems and in the ability to quickly get it right the first time. For the rest of us, a trial and error approach is OK and can provide a great education.
I would suggest you take some time to look around your house and the attic(s) and crawl spaces with the goal of running wire in mind, to see if you can find a likely path. Specifically look for the top plates of the lower story walls and passages between attic spaces. If nothing else, it is good to get to know your home a bit better.