How can I boost my website's SEO and make the site more efficient for customers? What are some free marketing tools?

[Marlee]

I agree with Jake, good SEO is more than automation and making it easy.

That being said, there are some tools of the trade which make like easier for people who are internet marketers in one way or another. For example, if you do a lot of heavy content creation in order to build an authority site then some of the content SEO software might help ensure that you're fully optimizing those pages with relevant LSI, etc... For keywords, I have paid tools but almost always end up back at Adwords (Google's Keyword tool... yes, even the new nerfed version still works). You can try Traffic Travis free version (http://moneyblogger.info/blogging-tools/)

For video marketing, using good software can be the difference in more views and better ranking. I don't mean that you need to fork out for Camtasia, but at least make sure you're creating visually stimulating videos/content and that it has audio which is captivating.

If you market to social networks (which you should, see link at bottom), then things like FB Echo which help "automate" Fan Page posts and simultaneously populates that content to a blog, can be very handy in terms of getting more done (thus earning more money and getting more visitors).

Since you specifically mentioned "marketing tools" I'm not sure if you meant like backlink creation, list-building software or what. But I highly recommend that anyone who has a blog start building a good opt-in mailing list. Those are people who you can reach out to from time to time to pitch special offers (especially relevant during holidays as they expect it), so don't leave that money on the table.
You asked a lot of questions and there's no way to answer them all completely, here, but hopefully this helps.