Do you mean to get products to market? If so, then Clickbank. Especially if you write blogs about how to make money on the internet. If you mean where to advertise, then facebook, yahoo answers, any blog page that lets you have affiliate links. Or you can create your own site and “snipe” the product you are marketing about. This is done by typing in your product and finding a website name very very close to it but hasn’t been used yet. I just wrote an Ebook called “Mr Money Banks” I offer 75% commission per sale so you will get $33 each time. If interested then email me and I will send you a free copy.
i think the best one i have ever heard of is clickbank, others are amazon associates, commissionjunction and you can search about any product and write with it affiliate program and you will see the affiliate program of that product e.g “weight loss affiliate program” .