First of all, you should always ask questions before you join an affiliate program. Do a research (in Clickbank or Amazon, for example) about the choices of program that you want to join. Get your questions answered, because you must be sure In this product.
How much does it cost to join? Most affiliate programs are free, because the more people will start promoting them, the more products they will sell. This is pretty much obvious. That’s why you shouldn’t join a program that demands money in advance.
When do they give you the commission checks? Well, each program is different: Some of them give their checks once a month, some every quarter, etc. Choose the one that you prefer. A lot of affiliate programs are setting a minimum earned commission amount that an affiliate marketer must meet in order for their checks to be issued.
How can you check your affiliate stats? An affiliate program should give you statistics that must be available online anytime you want. Constantly checking your stats is important. You need to know how hits and sales are already generated from your site. You need to know which tactics work and which not, so that you can adjust something.
How easy is it to make money? Well, I’d say it is hard if you do not have a plan. As I was starting out, I was trying everything: article marketing, blogging, Twitter, Facebook, but it was useless, because I was doing these methods at the same time, without any structured planning.