My company is switching carriers for our T1 service. Most of the T1 is just for phones but part of it's for data (no broadband save satellite in my neck of the woods). Our old carrier supplied the firewall but the new one only supplies routing (firewall 'service' is $250/mo which is just silly for an office of 20). We host nothing internally so I've purchased a SOHO3 from Sonicwall (I'm the default network guru but it's not my primary job). It's got a VPN option, which is interesting as I dream of telecommuting occasionally and it might be useful for a few (2-4) of our sales guys when they're on the road to sync their CRM sofware & enter orders.

Here's the question part:
Where can I get a good grounding on VPN setup & troubleshooting? Any tips for good sites or books? Also, do I need to use Sonicwall's client or do I have other options?

I know this is a pretty broad subject, but I'd like to see what's doable with my time (limited) and resources (computer & otherwise).

Thanks!

-Zeke