Yes, fleas do feed on by humans, but they are not usually the initial target. There are many different species of flea, each one having evolved to target a specific host, such as a dog or cat.
They will, however, feed on a human host if it is within striking distance of the flea and is therefore a viable target. Flea bites are not uncommon on humans who live in a household that is infested with fleas.
The best course of action for eliminating any flea infestation is to buy a medication targeted for this specific animal that is infested with fleas. When the infestation on the animal is contained, there will be no more fleas to feed on and bite people in the household.
For dogs and cats, Advantage is a great medication for killing fleas. It kills the adult fleas before they have the ability to reproduce, effectively stopping the lifecycle of the fleas.