Is Affiliate Marketing Hard?

I have recently been looking for something I can do part time from home. I am a stay at home mom who could use a little extra money. I can only work for a few hours each day when the kids are napping or in bed for the night. A lot of people have told me the benefits of affiliate marketing as a part time job, but I am not sure whether I can do it or not. What does it involve? Is it very hard? How much time would I have to spend on it in order to make any money?