Hello Hamiltons
A very short question for one of the worlds most controversial and hotly disputed topics!
I did a 101 guide for people new to the world of SEO which gives you the basics:
SEO 101 for newbies
I've just also posted a link to a superb beginners guide on Moz.com:
Beginners Guide to SEO
Between those two you should get a good grounding. When you have some specific questions, fire away 
