Google's Webmaster Central blog featured a best practices post on moving your site to a new domain - it should be noted that this is different than moving sites to a new IP address. This is an incredibly important topic and one that all website owners and Web professionals should understand in great detail as it is necessary to help avoid complications during these shifts. While some analysts are suggesting that Google and other search engines should develop a formal domain change process, it could be argued that it's not really their responsibility. Which ever way you see it, I've summed up the main points of the post below:

• Test the move process by moving one directory or sub-domain first and use 301 redirects to notify Google of the change.
• Once complete, redirect your pages to the most relevant new page, if possible.
• If you are rebranding or redesigning the domain, move first and redesign later.
• Update internal links to pointing towards the new domain.
• Request external links change to point to the new domain.
• Retain control of the domain for at least 180 days
• Register and verify the new domain with Webmaster Tools and submit a sitemap.
• Review crawl errors to make sure redirects are working properly.