Hey Chris, welcome to SpeedLine!
Pay@ the Door - You can either supply your drivers with tablets or phones that you own, or they can download the app of their phones. Then, they need a bbPOS chip reader that pairs to their phone with BlueTooth. You can talk through different ways to set it up with your Account Manager.
As for tips and tricks, this forum is always a good place to ask! You can also sign up for the Customer Support Site and go through the tutorials there. If you just signed up, you’ll be getting emails soon telling you how to access it, and listing different newsletters you can subscribe to.