Just to remind everyone, The RTB Wiki has a large cove of info on mapping, it can answer a LOT of Personally, I highly suggest you take a gander at the wiki before requesting help here, as it can really be helpful and ease up wait-time for you to get a answer (not to mention help your reputation if you are asking a newb question!) The RTB wiki in general is a wonderful resource, and it needs your help to survive,
Remember a Wiki a day keeps the Doctor away! (NOTE: Recent studies have not linked Wikis to doctors in any way shape or form at this time)!