Learning about SEO

I have been blogging for two years now.Since it's a personal blog,I don't mind the rankings of my blog.I just write what I would like to write.But my other friends who have many blogs use seo tools to have higher rankings in search engines.I already heard SEO before but never got interested.But now,hearing from my other friends and also what I have read,I am now convinced by the good things of learning the works of search engine optimization.Some of my friends are lucky coz they use some seo tools to boost their website rankings and they are now reaping the rewards.

I really wanted to know the ins and out of SEO and hopefully I gain from it eventually.I want to optimize my blogs.