Hello immanuelruby, and welcome to WebmasterWorld. ;)
Since you are a relatively new member of the forum, I am not aware of your level of expertise - so please pardon me if the page I have referenced below is too basic.
That said, this is one of my favorite resources on how to think about AdWords, leading to some useful insights on how set up an AdWords account for success:
Tips for success
The topics covered on this page - which, in my opinion, are essential to using AdWords effectively:
1. Identify your advertising goals.
2. Organize your account for maximum effectiveness.
3. Choose relevant keywords and placements.
4. Create straightforward, targeted ads.
5. Optimize your website for conversions.
6. Track your account performance.
7. Test and modify your campaigns to get the results you want.
<edit> Correct my user name - hahah! </edit>
[edited by: AdWordsAdvisor at 3:25 pm (utc) on Mar. 17, 2009]