A lot of SEO companies do dodgy work that gives short term advantage but in the long run can damage your ranking.
My dad was paying £100 a month for SEO - for the first 3 months he got loads of calls, and then it started to go quiet again. After 18 months he finally cancelled the service, and hey presto, his phone started ringing again within a few weeks!
Don't believe the tips & tricks - just give Google what it wants - good, unique, regularly updated content. Try a facebook widget, twitter integration, a regularly updated gallery, a page with special offers that changes monthly. Video's can also give a great boost to google ranking & can be a fantastic sales tool if done right. Add a privacy policy page (google likes these), add statcounter code so you can track the viewing behaviour of the visitors your site gets....
You could also take steps to make your website more friendly to mobile/tablet devices (currently about 10% of all internet browsing is done on these - and that figure is rapidly growing) like this one I'm working on at the moment:
http://windowcleaningscotland.co.uk/index.html