I recently converted my 15 year old website over to DNN. While I am very pleased with the results, I am terrified that I may have screwed my Google rank in the process. For the past 15 years, the site (www.benedict.com) has always shown in the first 5 results for keyword "copyright", and has had a page rank of 7 or 8.

A week after the cutover, I now I don't show up at all under a search for "copyright" and I have no page rank. Should I just chill out because this is a temporary adjustment, or should I panic and try and restore the old site?

TIA!

   - Benedict

Yes panic.  Go get ifinity URL Master from snowcovered immediately.

Your old site had one set of urls, eg example.com/index.htm, example.com/page1.htm, and so on

These are the pages that G has ranked highly. 

Your new site has urls like example.com/default.aspx, example.com/page1.aspx

Google has no idea that those pages exist, and it has no idea that your old url has changed to the new one.  It is still looking for your old /index.htm url, because it hasnt found it for a while, it has dropped it.

Use the URL master module to map each and every old url to it's new url.  PR7 - PR8 is an extremely rare and valuable thing.  Dont lose it.

Oscar

Looks like you had back links to .asp pages as well... and from universities - nice work.  A rewrite (versus redirect) may be the better answer for some links.

I've had success with 301 redirects but found for really special pages it is best to keep the URL as first published.  Search engines favour age before beauty and the original URL maintains 100% of that value.  A Google Webmaster account will tell you what pages have the most back links so you can focus on the top few.  Anything that is the same from 1996 should remain intact!  I manage a similar website (legal resource) with links from 1998 and found direct evidence the old URL performed better then the new, redirected one.

Another tip; you should replace your 404 page with something more friendly then at least if a link or two is wrong the visitor will still get some value.  Google also has a good resource for that.