I went through a Rand phase in high school as well (I think that's probably the best time in your life to read her)--and I still think The Fountainhead is a fine novel. I agree though the movie is glorious camp. Reading about the making of the film is interesting unto itself--Rand and director Vidor's fights, how it was such a dream project for Vido--I think it was made with a lot of love and honest belief in its message (but then that's probably true of all *true* camp).
To be honest, when I first heard about Objectivism and started reading that Rand's books were so full of Message, I felt kinda betrayed. These books I loved and took so much to heart were seen by many to be merely propaganda? And I certainly don't agree with Rand's beliefs about society--I think I feel about the opposite. But now I can look back at them and appreciate them as stories too, and what I got out of them. Regardless I think atlas Shrugged being made into a film is a thankless job and will probably just accentuate (as Fountrainhead does) how silly it all is.
I remember she threatened to blow up the Warner Brothers lot if they changed a word of her script (they did, she didn't). The movie of "The Fountainhead" was indeed made with complete sincerity on the part of everyone involved and you're right to say that probably intensifies the camp (that and Rand's total lack of humor) -- it's too bad, in a way, that it didn't turn out well, but I also think that was probably inevitable.
I confess I've read The Fountainhead more than once and although I haven't picked it up in years I'll probably wind up reading it again some day. I agree, high school is an ideal time to encounter Rand. The Fountainhead was probably the first novel of ideas I ever read. Rand is good at explaining systems and at action, too, and some of the peculiarities of her prose can be explained by the fact that she wasn't writing in her first language and certain aspects of English were always troublesome to her. (To the end of her life she'd say things like, "It's an ungulfable bridge.")