Forum Upgrading my vBulletin 3.7.4 to 4.0
 

I have a forum on vBulletin 3.7.4 version and want to buy and upgrade to the vBulletin 4.0 Publishing Suit. All my attachments are in filesystem and database is on a second db server.

Where can i find information about upgrading ? Any special things i should be aware of ?