Matt’s Cutts of Google has a great post on moving a website to a new host without losing all that hard SEO work you’ve done. Here’s Matt’s steps:
Step 1. Find a good web host and sign up for an account.
Step 2: Make a back-up of your site at the new webhost.
Step 3: Change DNS to point to your new web host.
Step 4: Wait for the DNS change to propagate through the net.
Step 5: Once you are sure people or Googlebots are fetching from the new webhost/IP address, you’re done. You can shut down the old site.
View his full post with all the details here. http://www.mattcutts.com/blog/moving-to-a-new-web-host/
