How many moderators does one licence allow?

[apsara]

I am looking forward to start a discussion group and wish to know answers to a few questions
1.How many moderators does one licence allow?
2.My knowledge of a computer is just an 'end user'. i surf a bit and found a niche where i think i can start a forum. will i be able to do this using vbulletin software?( Does one need a help or get some answers from manual)
3.Will I be able to advertise and generate revenue in my forum at a future date?
4.Do I need to have a server dedicated? ( I am not sure of the technical soundness of the question here).
5.My proposed forum will be built on medical subject. Can I integrate a medical dictionary into VB?

I am a user of a forum powered by VB and saw a link at the bottom of that forum and came to know of VB. I felt some ray of hope but am still intimidated

Thanks for reading the lengthy question of a dumb newbie