Question : Exchange Server migration

Hi, I am shortly going to commence a migration from Exchange 2003 to 2010.
Presenlty 2003 sits on an old server with aprox 100 mailboxes totalling 60gb of database.
There will be a new server with Exchange 2010 on it.
Can anyone provide the guidelines on the best way to migrate the mailboxes across?
Can these 2 exchange servers sit within the same organisation?  If so, when can I shut the old one down and ensure mail is dleivered to the new one?
The servers are likely to be within the same domain.
Many Thanks

Answer : Exchange Server migration

Sage know about it and have a patch to fix it I believe. You'll probably have to ring them to get it.