Yikes, that is a newbie question, but a totally valid one! Yes you need to purchase web hosting services, preferably from a reputable company that works within the adult industry so that you can get the support and service that you will need. IMHO, the best one is NationalNet, but they only deal in complete dedicated server hosting and since you are new to this you prolly want to start out with a smaller virtual account. Bec will be along shortly with her recommendations.

Oh, and a big thumbs up to blogs organizer too, I use it to run over 100 blogs and its by far the best product out there!