To set the channel in airodump-ng you have to add -c. For example: "airdrop-ng -c 11 wlan0"
To run airodunp-ng you have to:
airmon-ng stop wlan0
airmon-ng start wlan0
To fix the resource busy problem you have to run "airmon-ng stop mon0", then "airmon-ng stop wlan0"
(stopping mon0 is necessary, but I do anyway.)
I hope this fixes it. If not, just let me know.