I need some SEO tips?

Hi!
I have an article indexing website, I have the title, a small image and a very short description about each article, the articles are in different categories.
I have a dynamically created page for each article with a link to the article.
I want to SEO optimize this page.

I`we modified the url using .htaccess to the following form:
/category/article-title-article-id/

I think the biggest problem is the length of the content: the title of the articles is around 50 characters and the description around 100 – 150 characters.

I don`t know what should I do to optimize the page.
Please tell me some tips
(I can`t show you the page, because I`we did not created it yet – I want to make it only when I know exactly how it will look).

The page will something like this (I`m planning to make it like this):
– the header of the website at the top with log in button and article submit button
– on the left side a sidebar with the available categories
– on the right side a sidebar with facebook fans, ads and news
– in the middle of the page the title and the description of the article with a big “go to article ” button, some adsense ads and a facebook like, a tweet and a google +1 button

Thanks for any help or any good or crazy ideas – I want to hear them all!
Thanks!

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