First I would give a good flea bath, be careful around the eyes, But scrub well, and leave on for about 10 minutes to kill any live fleas. Blowdry, and then put on a topical flea treatment, You can buy things like Bio spot wich are like frontline or advantix but cheaper at petstores. Remember, read directions on the treatment do not let him get wet or have another bath for a few days after putting treatment on.
Flea meds/shampoos can be pretty toxic and I wouldn't want to subject my dog to both of them at the same time. Plus, grocery store type flea meds are much more toxic than the vet-quality flea meds, so use with caution. I don't use anything but Frontline and Advantage, but there are other vet-quality flea meds, too. You can use BLUE Dawn (only blue, and no other brands) to kill fleas. It's safer than a pesticide shampoo. Leave it on for 5 minutes after lathering so it can kill the fleas.
After any bath you hould wait a couple days before applying topical flea meds, because the meds spread through body oils, and most of the oils will be gone after a bath. It takes a couple days for them to come back. If the flea meds are applied before that, they won't be as effective.