Hi,

http://minerva.netgroup.uniroma2.it/discreet/browser/torlab/trunk/INSTALL
http://list.dia.uniroma3.it/pipermail/netkit.users/2007-November/000313.html
Outdated, but perhaps similar to what you're talking about doing?

Yes, that would be a good starting point.
 
Besides TorLab, there's also a Java-based simulator, which is somewhat similar. Sorry, I always forget the name of it.
 
Why VB? And do you mean VB or VB.NET? 
 
Sorry for that, I meant VM (virtual machine) based simulator.