When launching a site redesign, what is the best way to roll it out?

[ControlByWeb]

We are currently working on a site re-design and are getting close to launch.

When launching the newly designed site, what is the best way to roll it out?

301 Redirects with an under construction page?  Just upload the entire site at once? or al little of both?

Thank You

[Develop41]

Make sure you redirect the existing pages to new URLs using 301 permanent redirects. This would help retain the value of page to some extent and the existing visitors as well. Defining everything in a .htaccess file would be the best option, and can also use a code in a PHP file to further manipulate the redirects.

[malachiii]

The company I work for did a complete text and layout overhaul in October of last year and it was a brutal undertaking.  We were transitioning from ASP.net to PHP and implementing a new CMS.  This meant we had to do the entire site at once.  There were a few hiccups, but we found the complete overhaul to be fairly seamless.. some things to keep in mind are making sure the 301 URLs are working correctly, launch the website during low traffic times (weekend)  to work out any unforeseen kinks, and request feedback from your visitors to see what they like / dislike for future changes.

[NeilTompkins]

If it's a total overhaul with new URLs, then you MUST use 301 Permanent Redirects for all the old URLs.  However, if it is a features overhaul, I'd update gradually to ensure your rankings don't drop.

[danrawk]

if it's a features overhaul, update each feature progressively over a few days or weeks.

if it's a total overhaul, 301 to all equivalent pages is the way to go. you shouldn't need an "under construction" in that case so long as all your content is ready.  the 301 permanent redirect will let google/spiders/crawlers know that this is the new, most important content.