I've asked my question in the title :).
Additionally, how much reputation will I need to do so, and what guidelines are linked with this?
Yes, any user with at least 100 reputation gets the privilege to create new chat rooms.
As the privilege page says:
When should I create a new chat room?
When you find yourself wanting to have an extended conversation about a topic that is not covered by one of the existing chat rooms, you should create a new room for it.
And finally at 1000 reputation you can create gallery chat rooms - these are rooms where you (as the owner) can decide who can and cannot talk.
For those too lazy to click the link: it requires 100 reputation to create chat rooms both here and in the main SO site. :)