There is a pill available from most veterinarians called Capstar that gives a quick kill of all the fleas that are on the puppy at the time its given. It is very safe and effective. This will help to get a good start on getting rid of them. In addition to this I would also recommend using Frontline, which is for puppies older than 8 weeks. It is also available from veterinarians over the counter. Do not get the products from discount stores as they are much more dangerous and less effective.
Along with doing these things for the puppy make sure you vacuum everything thoroughly, and wash any bedding the puppy sleeps on in hot water.
If you have further questions let me know. Please remember to leave me a positive feedback rating once you are completely satisfied with your answer. Thank you.