On one of my campaigns I owe google $350. My card is linked to the account, how does google get the money from me? Automatically or do I have to tell it to take the money somewhere? Thanks
They will automatically charge your credit card when it hits a certain amount (which varies). If your account is new, my guess is that they will do it around $500 - perhaps less.
Not that I know of. See this for more info on AdWords billing: http://adwords.google.com/support/bin/topic.py?topic=7001