You should go ahead and read it. I personally don't care for Ayn Rand, but it seems like a whole lot of people want to promote her, and claim she's enlightened them. Her philosophy is indeed childish, irrational (despite it's claim to rationality) and is founded upon what most people with any modicum of philosophical education consider a rather pitiful misunderstanding of pretty basic philosophy. And yet, I think it's pretty important to read it. There are 3 reasons why.
1) If She's Crazy --- if it's really the case that her philosophy is garbage, then there's a value to reading it, and finding the flaw of her arguments. If you only read works you expect to like, then you're not exercising your critical thinking. There's a lot of garbage philosophy out there, and Ayn Rand presents enough material for you to think about, and critique, that even if you finish the book with the conclusion that she really was an insane, arrogant, self-promoting wack-job, you'll at least be confronted with having to assess WHY you think so--- and this will in turn strengthen your own philosophic convictions. You'll have a better basis by which to know what you think, and why you think she's nutty.
2) Maybe She's Misunderstood --- The fact that many people (such as me) consider Ayn Rand about as philosophically valid as Sarah Palin doesn't mean it's true. Many Rand enthusiasts insist that Ayn Rand is a brilliant thinker who exposed society's flaws, and there's some sort of intellectual cover-up, trying to prevent her wisdom from being accepted by the masses. And there have indeed been many brilliant thinkers who were maligned for long periods of time as imbeciles or worse before they were eventually realized as the great minds they were (Nietzsche comes to mind). The fact that many people despise Rand shouldn't make you dismiss her--- it should in fact urge you to make that decision for yourself. There is a chance, I suppose, that a whole, whole lot of people are wrong, and that Rand was on to something. In addition, the fact that a philosophy is insulting to some people has no bearing on it's relevance. And just because many obnoxious and lousy people follow someone, it doesn't mean the person they follow is necessarily bad.
3) You'll be able to end arguments --- There is so much anti-Rand sentiment out there that the followers of Rand make a quite valid point that most people haven't read and considered her writings for themselves. As easy to read and accessible as her works are, it really does fall on anyone who wants to voice an opinion on the matter to go through the minimal trouble of reading her works. I've gotten in my fair share of debates with Objectivists, and find that their go-to argument is that anyone who disagrees with them obviously hasn't bothered to read Rand. If you have read her, then you can end that argument quickly, and proceed to the real substance of a debate on Rand--- and really, a lot of the topics that Rand touches on, whether you agree or disagree with her, are extremely good debate topics, and do get ideas flowing. Knowing why she's wrong is infinitely more valuable that taking someone else's word for it that she is.
You can't really pigeon-hole Objectivists as 16 yr olds and assholes. True, many are. But just as often, they are impressively smart people who have just latched on to Rand because it resonated with some part of their mind, and have felt more secure believing in Objectivism than offering it the critical evaluation which would pretty much demolish it. There are also a scary number of conservative think-tanks which promote Objectivism. It has a political agenda. It's not just for teenagers. Just people who are moralistically stymied as teenagers.
Is it *******ed up? Yes. I think so. But ******ed up, like beauty, is in the eye of the proverbial beholder. The part of the Fountainhead that most people find objectionable is the scene in which the ostensible 'hero' rapes a woman, who in turn adores him for his initiative. I consider that kind of ****ed up.
So yeah, go on and read it. Even if you determine it's junk, there's a value to knowing that for yourself, rather than just believing popular opinion.
Hope that helps.