Best & Safest Flea Products?

What's the best flea product that works well, but doesn't break the bank? I have a toy breed dog, a Chorkie(Chihuahua/Yorkie) to be exact, and I need to find something that I can use on him. He's seven months old, but I'm wary of trying stuff without knowing if it's going to effect him in a bad way. I also have a cat, and I used to use Revolution on him that I would get from the vets office, but I stopped going to that vet because his staff was always rude and pushed me into getting shots. So now, it's summertime in Florida, fleas are multiplying and I have no clue what to buy or where to buy it from. HELP!