Supplemental Result and duplicate titles - What is my next step?

[eden]

Hello everyone,
I am trying to be a good student of webmasterworld… I am not doing major moves in my site without reading many posts.
I have a new site with useful and unique information.
So first I put all my energies to have real and quality content so now that I see that G is indexing my site is time to do some SEO.

I want to change all tags of the site and I want to remove my site from the supplemental Result.
What will be best to do?
1.To change all the title tags and make them unique?
2. To use the mod_rewrite and create pretty urls?
Due the fact I have a dynamic site every change to the tags will change 240 pages at once – can I be punished by G?
How much time it will take me to have my pages be listed in the main index?

Here is a small summary of my site:

I have a site that the content is generated by the users .it’s growing every day.(hopefully)
My site is online already for 6 months. I have around 300 pages. Around 200 are generated by users.
I have a dynamic site.
I have 60 pages in the main index.
I have 240 pages marked as supplemental Result - Those are my “important” pages – the dynamic ones generated by users.
My url looks like (mysite/index.php?acc=4&art_id=24)
My title tags and description tags are the same for all the user generated pages.(around 240)
I have around 20 links (mainly blogs - I am working on this… but I am trying to concentrate on quality and it’s hard)
My PR is 0.

I am aware of the hot topics -
Duplicate Content
Supplemental Results

Thanks for the help and be delicate…
Eden

[tedster]

Yes, without a doubt, unique title elements are essential to rank well. So definitely take care of that. Every page cannot be about the same thing, and the title element is THE most important on-page factor by a healthy margin. It's the one element of a page that almost always shows in the search results, after all, so that should tell you how important it can.

However, after that most basic fix, I think your challenge is that PR0 -- if urls do not have much PR, then that fact alone can give them a Supplemental Results tag.

6 months is still young in Google's eyes. It sounds like you my still be hitting that set of filters that people call the "sandbox effect". Do you watch your server logs, taking note of what traffic Google is sending and for what searches?

This is, in my opinion, one of the most important things to watch -- your real traffic. Everything else is at least one level of abstraction from where the rubber meets the road, and trying to plan changes only from that level can sometimes make as much trouble as it fixes.