Don’t go insane and join a million at once… think first about what would make sense for you to endorse. If you’re a travel blogger for instance, becoming an affiliate for hotels, tours and travel gear may be appropriate. Most companies will have an affiliate program, or be part of an affiliate network. Your best bet would be a quick Google: “company + affiliate program”.
Affiliate marketing has now invaded Hollywood? We know it invaded US politics in Washington as some politicians (current and retired) are silent affiliate marketers or in MLM. Maybe we can look forward to hearing in the next few years about more celebrities going from actors and actresses to home-based affiliate marketers. Wouldn’t that be something?
I personally prefer to do it that way--you can create a more convincing review that's more likely to make sales. It's not always possible or practical, though; for example, would you break up with your significant other just to test a product for getting your ex back? ;-) In cases like that, or if the product is expensive, it's usually best just to use the vendor's affiliate resources instead.
More of a lifestyle and online entrepreneur motivation site, Pat Flynns blog is still a great resource for affiliate marketers. Some articles relate specifically to affiliate industry while others serve a more general purpose and might be a nice break from all the marketing content you’re consuming. His Smart Passive Income podcast is a great on the go motivator as well.