milosevic - 2:53 pm on Sep 7, 2010 (gmt 0)
I'd say the best place to start is to read sites like searchengineland and sphinn. If you go looking for online SEO guides in Google you'll probably only get out of date rubbish.
Just read stuff on those sites every day, follow links inside blog posts to older articles where you think you might learn something, and always be sceptical and read the comments etc in case you are looking at total BS (which wouldn't be that rare).
Don't skip out on learning HTML and CSS. CSS doesn't seem that relevant but so many people write crap HTML that's poor for SEO purely because they don't know the easy way to code what they want to achieve using CSS. The WC3schools site is a great resource.
Try and think from the Search Engine's perspective too. Way too many people are so stuck in the mindset of getting better rankings for their site and the competitive side of things, they forget that the idea of a search engine is to return the most relevant and valuable results to searchers and improvements to algorithms etc are carried out with that general aim in mind.