all you should have to do is backup the database and if you have made any mods to the bb zip up the directory that the board is in. download any config files that you have in the vbulletin directories, however i think most of the data is stored in the db as far as the layout.
there are several ways to export the database.
1. from the command line
'mysqldump -u username -pPASSWORD vbulletindatabasename > vb.sql'
2. from phpmyadmin
select the vbulletin databse from the left dropdown. click the export tab at the top. the default options should be fine, click the go button at the bottom. save the output as a txt file.
once you have that and then you have the database created on the new server and have vb installed you can import the data.
from the command line.
login to mysql: 'mysql -h localhost -u username -pPASSWORD
'\u newVBdatabase'
'source vb.sql'
that will run for a while depending on how large your database was. after that completes it should be setup for the most part
if you use phpmyadmin
select the db from the left menu. click the sql tab at the top. either use the file upload box to upload the sql file or paste the contents into the text box and click the submit button.