To Green_Grass's excellent response, I'd like to add a couple of things:
* Most advertisers are on a 'post-pay' option, which means that you pay after you have received the clicks, rather than before. This is important to keep in mind if you do pause or delete your ads - as you'll almost certainly receive a follow up billing which covers the clicks you've received in the time period between your last payment, and the time you paused or deleted your ads.
* To maximize your chances of success, I would highly recommend learning as much as you can about AdWords. It is a very nuanced program, and, IMO, you should expect to put in some serious work in the early phases of your advertisin as you come up to speed on those nuances. It is a very rare advertiser who sets their campaign up perfectly on the first go, never monitors and adjusts anything, and then sits back and watches the business pour in.
Some resources of note:
* The searchable AdWords Help Center:
* The AdWords Learning Center:
* This forum, of course. ;)