the best way is to learn as you go along. Take courses keep learning its a gradual process make your self aware of all the techniques blackhatting whitehatting and blue hatting check out forums and speak to other seo

check out this forum it has an seo section:

http://www.montagemarketing.co.uk

there are a few blackhatting forums out there that will show the darker side but check them out as well as it will give you a full understanding of what you can do and how to do it or pm me if you have any questions
References :
http://www.montagemarketing.co.uk

The best place to learn SEO in my opinion is over at SEOBook. Aaron Wall knows what he’s talking about in terms of SEO.
References :

You can get information on web.. their are many ebooks available online.. you can go for forums like http://forums.digitalpoint.com. then few reputable company websites like http://webcyonix.com, can read articles from their article category. You need to be updated regularly with quality..
References :

I ran a web design company and for over a year I outsourced all SEO clients to a company I liked. I have since then merged with that company creating http://www.Webmosa.com. Essentially what you should know is this:

SEO changes with time, search engines compete to be the best, and they update their software
There are good (white hat) methods, and bad (black hat) methods to learn and master
Every search engine is slightly different, you need to find a balance if you are going for overall dominance.

I would recommend to work with an SEO company like I did, I say this because that way you are learning from professionals who know the service very well. That way for free you would be learning the trade secrets while developing a business ally.
References :

hello friend..
well If you want to become a SEO expert.First you have to learn what Is Search engine and how it works…?after that only you can understand that what Is Going to be done in SEO work.SEO is The way to increase your websites traffic – Your business goals – leads.to boost up your websites ranking in various search engines like google,yahoo,MSN and other more than 365 search engines.SEO is very deep field my friend If you want to learn SEO you have to be a great reader.i am giving you some best sites references for learning SEO.They will provide you E-book too for learning SEO.this is a growing field in IT.If you become a SEO expert you can develop a great career in this field.
basically SEO is departed in Two main parts :-
On page SEO
Off page SEO

But If you want to learn SEO from Its basics refer sites given by me below and read all details given by them.It was nice to help you friend.Even If you want more information let me know i will surely help you.Thank you.Have a nice day.
References :
http://www.seomoz.org/
http://www.seobook.com/
http://www.seochat.com/
http://www.bivings.com/thelab/presentations/SEO_Basics.pdf
http://www.googlerankings.com/basic.php

There’s plenty of books around which explain it in depth, although the books aren’t free they’re really good resources. Maybe look at the local library for some information?

Here’s something you might want to read as a basic guide:

http://webupon.com/marketing/how-to-use-search-engine-optimization-to-your-advantage/
References :