Piece of cake to do it. Three years ago wired our house with CAT 5e, then added wireless 802.11b last year. When in my office (at home) I normally use the wired connection. However, wireless allows me to take my laptop anywhere in the house. Nice to watch TV and surf TFP at the same time
The AP/router sits in the basement and I have no problems getting a decent signal anywhere on the second story. Haven't wandered around the yard with my laptop, though. You might want to try the different channels on your AP to see which one works best. We do have some interference whenever we have two microwaves in operation. Usually with just one, there is no noticeable degradation.
Good luck,