Changing domain

Hello, I’ve a blog on http://www.ovelha.org/pasteler0 since 2005, but now I’m thinking of changing to a new domain, a easier one, as my site have quite many visitors/day and is linked many places on the web…

Here goes my questions:
-How can I backup my posts in and install in on my new domain (this is the easier one)
– How can I make in a way that when some one for example goes to http://www.ovelha.org/pasteler0/2005/11/17/howto-external-winamp-control/
it will be redirected to http://www.newdomain.com/2005/11/17/howto-external-winamp-control/
Is there any way I can do that?

Any one have any more advise about this change?

Thanks so much!

daniel