Hi kirsty1980,
Featured in our May 2012 SaleHoo Seller spotlight, Alan Smith shares that you need to be careful with Google Adwords campaigns and backlinking. He said that if you don't do it right, it can cost you a lot of money or cause you problems with the search engines. Link hidden: Login to view
We also recommend the free training site Link hidden: Login to view to learn more.
And here are other related forum posts that may help -
Link hidden: Login to view
Link hidden: Login to view
Link hidden: Login to view
Link hidden: Login to view
Hope this helps.:)