Hi Dan,
Sorry to hear you got hit by Penguin. Because Penguin is an algorithmic action, you often won't receive any messages in Google Webmaster Tools, unlike when they place a manual penalty on your site. But it's not uncommon to receive both a Penguin slap and an unnatural link warning.
Ok, deep breath.
1. First things first, you need to take a deep hard look at your backlink profile to see where you stand, if clean-up is worth the effort, or if you should start over.
If you engaged in questionable link building practices, you need to asses if you have any links worth saving? Do you have any editorial (non robot generated) links that you didn't pay for and/or didn't control the anchor text?
You probably know the answer, but for more complex cases a couple of resources that might help:
A. Manual Review - In the end, you're own eye is the best tool you have. You want to look for:
- links with keyword-rich, optimized anchor text
- Comment Signature and Forum Signature links (these are different from the more legitimate forum links)
- Sitewide links, such as in the sidebar or footer
- Obviously paid, or suspicious looking links on low-quality sites
Our friend Paddy Moogan wrote a great guide on how to do this step by step. You should check it out.
B. Link Detox - http://www.linkdetox.com/ For $40 dollars it will analyze your backlinks (be sure to upload them from Google Webmaster tools) and give you a full analysis of what links they think are bad.
Most of the links I'm seeing for your site are similar to this: http://www.computer-desk-furniture.net/date/2012/06/ which would be considered a low quality link.
2. You may decide to try to get the links removed, which to be honest can be a long, arduous process.
Even if you didn't get a link notice, you can file a reconsideration request to see if they will verify a penalty. Sometimes this will get you more information then you had before. In any case, it might be well worth it to do a complete link audit and cleanup, and even go through the disavow process if necessary.
in addition to removing suspicious links, I'd continue to build good, high value links as well. If you need inspiration, here's a good place to start: http://pointblankseo.com/link-building-strategies
Hope this helps clear things up! Best of luck with your SEO.