I learned my lesson the hard way…
I found a guy who was VERY prominent on the SEO boards. I didn’t find him there, but another way. However, he wrote many articles for some of the biggest websites (including webmasterworld and seochat).
He had a good record at helping out websites and a good name in the SEO industry overall. His websites, too, were ranking in the top 10 for SEO terms (seo optimization, search engine optimization, etc..)
We had a deal that I felt was advantageous to me… that deal was something like this: He had to rank me in the top 3 on Google AND Yahoo for a set of 5 phrases. I would pay him 50% to start and 50% ONLY if he got me ranked as was stated in the contract.
He changed around my site(s) to be more SEO-friendly…. Couldn’t get them ranked in the manner he was supposed to, but wanted the last 50% anyway.
One day, I went to change content on one of my sites… and it was completely removed (all page he downloaded and zipped up for himself and removed from the server).
He kept them hostage until we discussed payments again. In the end, he agreed that I was right, but still wanted 1/2 of the remaining 50%.
I learned my lesson, learned SEO, and do it all myself now.