I gave someone some advice which I wanted to share with you:

There are some simple rules I use which you may find useful:

1 - Don't spend money you can't afford (sometimes it takes time to get a campaign in profit.

2 - Make sure you include negative keywords (don't waste money on the wrong traffic)

3 - Be congruent (set an expectation in your ad and match it with the link - people don't like having their expectations unmet, so make sure you send them somewhere that ties in with what your ad said) I know this is common sense but a lot of people write their ad without thinking of where they're about to send that person and what they want them to do.

4 - Start big a trim down (make a big keyword list and then trim off what doesn't convert. Sometimes it's the keywords you don't expect that turn into sales)

5 - Use Adsense to test (it often helps to make a simple blog/site with information and Adsense and track what people click so that they tell you what to offer.

6 - As per 5 - Track everything so you know what's working (and not)

7 - Give it a big enough test (don't just send 100 people and make assumptions, but watch your budget)

8 - Try and get a $50 Adwords voucher, there are a lot of them being given away by hosting companies etc, so you can get $50 of ad credit by spending $5 in many places.

9 - Learn about copywriting (writing effective ads is more complicated than you might think, so you can start right away but take the time to learn how to do it properly and you'll ultimately make more money)

10 - Watch and learn. (there are a lot of existing successful PPC campaigns running which you can watch and learn from. There are also tools which will help you do this and also create and run your campaigns on a more effective level. check out http://www.speedyppcs.com/ )

I hope that helps.

Andy