Ideally you want to pick the channel that gives you the best signal-to-noise ratio, but where there are heaps of APs at varying strengths in different parts of the house the choice is non-obvious. Sadly there doesn't seem to be a FOSS wireless survey tool like Fluke AirMagnet, and while you can use kismet to collect signal strength data you will have to do some analysis of the data yourself (my wireless card also didn't play well with kismet).
I decided to optimise for one location - where I use the laptop the most. So I set my AP to channel 1 and:
sudo iwlist wlan0 scanning > ch1.txtRinse and repeat for all the other channels (setting the channel on my AP is quick, but this might be impractical if yours is slow, requires re-auth etc.). Then compare the signal strengths:
grep --before-context=4 "myessid" ch*.txtPick the channel with the highest quality number (best signal strength).