Currently, I am also looking for ways to accept money on my site. I
have decided to go for Google Checkout. Google Checkout takes charges
only 2% for credit card processing, while paypal takes more. Also if
you are using Google Adwords, there will be no processing fee for sales
upto 10 times your Adwords spending. Suppose you spend $100 dollar per
month on Adwords, then google will not charge you for credit card
processing for sales upto $1000 per month. Thats just other benefit
besides the 2% advantage.
And how to integrate that service into your website, you can go to
and find out how to
do it. Good luck.