From personal experience:
If you have strong knowledge of HTML, CSS, Javascript, Image manipulation, atleast basic command on one programming language (PHP know-how is a big big plus), then, running vBulletin is FUN
but if you do not know any of above, then, you can still run a forum only that it may remain at default non-attractive template or you will have to get free skins or buy one but then, there will be many things that you will feel handicapped about though vBulletin can be run as is anyway....
getting my drift
?