I've rafted hundreds of times without a problem. I think it's one of the best parts of boating. How it works: A larger boat sets anchor and everyone ties to them. If the raftup gets bigger, other boats will be asked to set their anchors as they join in (to add grip and stability). Rafting is not difficult at all if the wind and waves are reasonable. That said, if it's breezy the best policy is to approach from the downwind side and toss a couple lines to the last boat in line. That will prevent any unintentional tie-up damage.
Fenders are critical to a good raftup, so you should all have AT LEAST 3 (borrow them if you have to!). Bigger fenders are better than small, especially if there is significant wave action. Always pre-rig your fenders on the side you'll be tieing to; on most boats under 25' fenders need to be set high- centered on the rubrail if possible, and F-R from the windshield to the stern- not near the bow. They can be adjusted after 'locking in' with the group.
As far as lines, each incoming boat should pre-attach a bow and stern line (no more than 25' long), and have them ready to toss. A third (spring)line is usually added after locking in to minimize lateral movement.
It sounds like a lot to do, but it's really not a big deal if the above preparations are made. Just remember- when rafting, fenders keep your fiberglass from damage, so bring 'em and use 'em. I carry 8 and often use them all.
