Hi,
Google adword is a program you can use to get listed in the search engine results for google.for which it supplies advertisement,you essentially create an account,insert your advertisement.pick the maximum amount u are willing to pay per click and then submit your credit card.your advertisement will then go live once credit card is approved every time some one clicks on your ad,Google bills your account.

Well I would say it is hard, it is about testing offers and scaling up.
I would not use it with CPS offer, only CPA if you ask me.
It is too expensive i think, there are ways to get cheaper traffic.
Key is do not use alot of keywords for your offers.

For example when you got a Cpa ofer which offers 20 free song downloads instantly,
don't take any keyword you can dinf on the internet.
Only take the once potential buyers would search for like : free music download, free music downloads, download music for free, free music

Don't go for 20 keywords or more, just take relevant ones. If you look at the keywords above, these are potential buyers they wanna buy music for free right away and you got that.
Others aren'T related and won't convert that much.
Than put your keywords in your ads, so the CPC gets cheaper and you rank better.
hope it helps

If your ad is not good or is irrelevant, you're in trouble...