I agree with Bridie! While I do feel there are some aspects to
SEO, like any specialty, that are in-depth and require a certain level of knowledge and skill (and as a result, might not be something you can work on personally) there is a TON you can do on your own and it's all readily available information. It's just a matter of implementing it.
Be sure to install Google Analytics on your site so you can keep track of the effects of your work. It's also a great tool for analyzing keywords and understanding what is already bringing people to your site (so you can work on increasing those margins)