Hi sweston, and welcome to BlackberryForums.... enjoy your time here
Here's a link to the Vodafone site, which you should find helpful.
Answer
It is really not too hard.... basically 2 ways to get up and running:
1. Via the Vodafone Blackberry site, or
2. Via the handset.
I have used both methods and both are relatively painless.... if you aren't confident using the handset, then try the PC/Laptop way.
As the Blackberry uses a push email solution (up to 10 email addresses), I do not think you will need to user a webmail application, as your synched email addresses will push their emails onto the Blackberry handset (onto your new blackberry email address), every 15 minutes (if I am not mistaken).
Sing out if you strike any issues... remember, we were all in your situation at one stage or another.... we will helop out as best we can