There are a lot of posts about this under the category boosting. Make sure you browse the forums, and preform a search before making another thread. This is what I did with my group.. Quest to level 8, RFC until 14/15, SFK until 25, then SM Cath until 42 (oh god..). Now I'm doing ZF.

If you bring them on autofollow they are bound to die. It's best to leave them (park them) at key locations where they will still get exp.

Let me find a good post, albeit the english is not great but it's still a good guide.