Question: What goes on at "precollegiate" camps or classes? What kind of benefits can be gained from them, and how do college admissions officers view taking part in these courses?
You can experience just about anything you want in the way of both pure academic and non-academic personal enrichment courses at pre-college camps and courses. Most colleges offer summer programs for various reasons.
First, they are good marketing tools to bring students and parents in contact with the colleges, thus possibly creating future applications for the schools. Second, they create cash flow for the colleges because many of these programs are expensive. Also, they provide a way for the colleges to give teaching assistants and junior and senior faculty opportunities to earn some extra money during the otherwise slower summer months.
The effect on your college application success can vary. If the programs you attend are non-competitive, that is, if all you have to do is pay to attend, then admissions offices will generally not think too much of them. However, if the programs are competitive (selective), they will notice that. An example of a great competitive summer program would be most states' Governor's Schools. These are very prestigious and can open some of the more difficult college doors for you, assuming that your other credentials are up to par.
Finally, one last possible advantage of a summer program would be if you can develop a strong positive relationship with your professor(s) there. When it gets to be application time, they may be willing to say a good word for you with a letter of recommendation. If they are on faculty at the college where you're applying, then the effect can be that much stronger. Bottom line: It's far better to attend any summer program than it is to lie around the pool or just watch MTV.