Anyone done Google Adwords advertising before?

Hi guys,
Since our new website links to our folksy listings I’ve been looking at promoting it with Google Adwords but I can’t seem to find any definite information about how it all works without signing up.

I know it’s pay per click but is it like facebook where you can set a budget and once your budget is used it all stops or does it continue to rack up the cost until your specified number of days runs out?

If anyone has had any experience of it and could share I’d be appreciative. Has it worked in driving sales in your experience? I’m promoting on social media but it doesn’t seem to be driving sales to Folksy although I am getting more commissions which I’m then listing on Folksy if I don’t personally know the customer.
Thanks,
Dani

Be interested too.