You should start by looking at the books by Jan Axelson.
Her site is www.lvr.com
If this is your first try at controlling devices from a PC, then you are in for a lot of fun and an lot of work. A big part of what I origianlly did with programming was controlling devices mostly using basic. It isn't all that hard, but it is very different from typical windows programming.
The manual for the device probably contains all the information you need about how to communicate with it and how to make it do the things it is built to do. You have to learn about the process of sending command - generally, what happens is you tell the device you are going to send a command, it replys that it is ready for the command, you send the command, it replys that it received and understands the command, and so on.
A quick check on the Web indicates you won't have too much trouble getting information on how to do this with VB
.NET. However, programming with a USB port is not exactly the same as programming a serial port - they are conceptually the same thing in that they provide a way to communicate with periferal devices, but they aren't programming in the same way.
Woody Z http://www.learntoprogramnow.com