There are certainly quite a few issues with the SEO of your site and many areas where you could look to improve.
Firstly, you mention that your site has been penalized. Why do you think your site has been penalized? I am not suggesting that your site has or has not been penalized but many people's first reaction is that their site has been penalized when in fact they have just suffered a drop in rankings. Having looked at your site, there are some issues that might have caused a penalty but I couldn't say for sure without more info.
So, have you been tracking your rankings within the PRO Dashboard? Have you noticed considerable drops in rankings for your main keywords? If so then this could indicate a penalty.
Have you setup Google Webmaster Tools? If so then have you received any messages from Google regarding a penalty or other issues? This will give you a clearer picture as to whether you have been penalized and why.
Having looked at your backlink profile, I can see several issues that could potentially have caused some problems. Firstly, your anchors have been massively over optimized with commercial terms. This was a massive factor in the recent Penguin update which Ryan has kindly given you a link to. You also seem to have a lot of spammy links from fairly obvious link farms which could also be causing you problems.
Finally, your on-page optimization could be significantly improved, I won't list all the issues here.
Anyway, I hope that's given you a few ideas to get started on.
Adam.