T U T O R I A L S E R I E S

Moving your WordPress weblog with the same domain name

When you change hosts, the DNS nameservers have to update around the internet fully, so your blog could be unreachable for 24-72 hours. This is nothing to do with WordPress - it's just the way it is.
Accessing your blog using a temporary address given to you by your host could also cause errors due to the way WP works. Best really to do this when you have the time, or plan ahead.

If you are moving to a new domain name, see this page instead.

First, you must create a database backup. Instructions for doing this are here or use the excellent and highly recommended plugin from Skippy.
Secondly, you need to download your entire WordPress installation. Everything. If you are having to move domains, this is not the time to try and tidy up your install, or to upgrade / change anything. You can do that once it has been moved, and it is shown to be working.

You should now have in your computer two items:

one or more database backups. Copy these backups again to somewhere safe on your machine so that you do the next stage on a copy.
all your wp files / folders / images directories

Now upload all your files to your new webspace.
Once that is done, follow the instructions here to restore your database.

That's it !
Remember that DNS changes will affect your blog, so do give it a couple of days for everything to be fully settled.