Ethan Pond is a good choice for a first backpack. Other than that first pull uphill, the trail is mellow. Once you get there, you'll find a caretaker, bear boxes to stash food in so you won't have to try to hang it, and, believe it or not, a tarp-covered eating area (at least that was the case last year). The tarp is there as much to encourage everyone to eat in a concentrated area, which reduces the amount of area that has to be policed for foodscraps (which attract bears), as for the comfort of the human visitors, but, hey, it's a nice perk especially for first-timers who may not handle cooking from a tent in the rain well. I assume that you are staying in tents. The two points that I would concentrate on for new backpackers are:
a) a chance to plan beforehand with them and then to go over their gear while there is still a chance to make changes, i.e., not as you leave the parking lot. The big mistake is taking too much that is too heavy, i.e., a whole roll of toilet paper, a BIG tube of toothpaste, and stuff they'll never need.
b) a careful "pack-fit" check in the parking lot as you leave. How you load and distribute the weight in the pack can make a lot of difference in the comfort department. If you're not too sure how the pack should fit, stop by an outfitter (EMS, REI, etc) and see if you can get a knowledgeable person to give you a quick lesson or read up on it. Better to have someone show you if possible. Here's a link to REI's written instructions:
http://www.rei.com/online/store/Lea...ryId=Camping&url=rei/learn/camp/fitbkpk2f.jsp
You need to plan on enough time in the parking lot pre-hike to work with each person on a good pack fit.
There are lots of other good options for first backpacks, e.g., Sawyer Pond, but Ethan Pond is excellent.