Where do people find out about these shows? I have never seen an offering for them. Is there a web site or magazine they use?
Mostly the Web.
For example, if you go to the CBS website right now, you can dig around a bit and find the Survivor 6 application; you can go to the Fox site and apply to be on the second Bachelorettes in Alaska; you can go to the ABC site and apply for The Bachelor 2; etc. Or you can go to a variety of reality TV sites (like, oh, I dunno, RealityNewsOnline and watch for articles about or links to such things.