Improve site visibility and markertability

I am looking to improve search engine ranking and site overall visibility and marketability. Right now I am using Google pay-per-click, but the conversion rate is not high, so I am also looking for ideas on how to improve that. Site: [login to view URL] The major keywords I am interested in include: ADD, ADHD, attention deficit, memory impairment, brain injury, etc. Please bid If you have proven experience in this area. Try to be specific, preferably by giving me an initial summary of your observations and ideas. There are 2 more projects pending based on success on this one.