Excellent post Dubbya!

I've recently gone through a similar situation with an ecommerce site. Some things to add which will probably overlap what Dubbya pointed to. This also is my own person experiences...

Try and keep the "most important" text elements the same initially. Titles, meta info, internal anchors, main text. They can be slowly and methodically adjusted once live.

Start working and continue to work on putting your page to page redirects together on a notepad file for example. Check, double check, and triple check it for any errors.

Create a custom 404 page that matches the new layout. Be clear and consise about explaining why they landed there. Include an on site search function. Include your most important nav links. Provide a "contact" so visitors can alert you to what they were looking for when they landed there if they want.

Have a site map(s) ready to upload.

Don't be surprised if the old pages remain in the SERP's for 30 days or more. Especially the deeper ones. Check to make sure the 301's are functioning properly for these pages on a regular basis. For example, I still have old pages in the SERP's today. The 301's were put in place and site map(s) were uploaded on the 26th of February.

Don't panic. You'll likely see some shifts and changes. Not neccessarily intially if you have all your ducks in a row. Don't overreact to them if/when they happen.

Keeping the "feel" or "flavor" of the look of the site similar will help to reassure and instill confidence in returning/repeat visitors.

A press release announcing the "improvements" visitors see can help in a variety of ways.

Dave

__________________
Religious-Jewelry Blog - Deep Link Directory - Religious Jewelry