I think that LOTRO is very well suited for the young, especially if you start out in the Shire as a hobbit, which is a very charming place. Although it does have some "scary" areas, such as the Barrow downs (wights and such). You develop virtues such as Compassion, Charity, Honesty, Innocence, etc that adds to your abilities. You don't get killed, you get defeated. And yes, it is multiplayer. And the artwork of some of the areas are just beautiful. I especially like the elven areas. Falathlorn and Rivendel are very nice, and Lothlorien (a high level area) is just breathtaking in my opinion.
It's good for old timers too. I love the game, and I'm almost 49 years old.