What are the top 5 things to do on a site for SEO?

Apart from all these 5 things, another important thing is patience. You really need patience in doing Seo.

Another very important matter to pay attention to is the age of the websites.

Even if you do everything in a professional way, add hundreds of EDU and PR 7 links to your website, write unique contents, you will need to wait for some time because you already are competing against sites which have been at the top for years.

I agree with you that patience is must for getting better results from website because seo is not one day game. First to make strategy, analysis then implements them for promoting any website.

at my point,the content is the most imporant factor.the next is the relevance back links

great content is the main part of SEO

I totally agree but its just one side of optimizing your site.. The 5 lists you have mentioned only tackles about On-Page Optimization.. Doing that On-Page isn't enough, you have to participate in doing Off-Page Optimization.. This tackles about building links.. You need to build links in order to get higher rankings, higher PR and generate more traffic on your site..

I have already discussed somewhere else that nothing in the top thing in SEO. All actions are required as food and water.

Ahh, finally, someone mentioned RESEARCH!!!!

Regardless of how well you implement SEO, there's no point in doing so if you have no traffic is there?

1. marketplace research
2. keyword research
3. content/article writing and submission both onsite, and offsite
4. link building (works in with reciprocal linking and backlinks
5. correct use of meta tag and html markup
6. correct implementation and usage of available tools and information provided by search engines that are there to HELP you! - use them!

Theres probably more, but these should get you heading in the right direction.

HTH

John