Just try to read posts here http://forums.digitalpoint.com/showthread.php?t=254247 and optimize for google as that is the most popular search engine.
just browse the forums yo'll find alot of info but to be no.1 for google serp, backlink backlinks and more backlinks. for yahoo content and more fresh contents
First, if you do on-page optimization, you must determine the following: 1.) How competitive is your keyword? 2.) The contents found in your site 3.) Proper link building 4.) The age of the domain or site 5.) Patience (SERPs updates 3 months or more, SERP updates happened 6 days ago so keep building links).