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.
I offer a ton of free resources, tips, guides and tutorials here on my website that can help you get started in affiliate marketing – and help you find success with it. While there are plenty of paid training programs out there, you need to be careful. Some of the people who create these programs make their money by selling the dream and not through doing true affiliate marketing for products or services outside of selling you the dream. That's not to say there are not some good training programs out there - but buyer beware. For now, I'd recommend you start with my free information here on my website – and to sign up for my free weekly newsletter here.
The problem with affiliate marketing, like many other home business options, are the so-called gurus and get-rich-quick programs that suggest affiliate marketing can be done fast and with little effort. Odds are you've read claims of affiliate marketing programs that say you can make hundreds of thousands of dollars a month doing almost nothing ("Three clicks to rich!"). Or, they suggest you can set up your affiliate site, and then forget it, except to check your bank deposits.