Some of the tools here at SEOmoz will be of great help to you.
Start out by using Google Keywords to research the phrases you want to rank for. This will serve as a guide to helping you chose and find new phrases and to see how many searches are performed each month.
Using Open Site Explorer here will help you identify your competitors sites to give you an idea of where they go to get their links.
Install the SEOmoz toolbar to help you are you browse sites as well.
Don't just stop at SEO either and remember to think about usability of your site. How easy is it to navigate, do any images give off the desired message, etc. After all,what is the point of getting traffic only to lose it when they get to the site.
It is also important to look at your sites analytics to help you understand what people are doing there - look at Bounce Rates and Exit Pages to understand where work needs to be done.
There are so many pointers I could pop in here that it would take forever, but do have a read of the blogs and guides here at SEOmoz
Regards,
Andy