I asked my doctor this same question last summer. Our son was about 6 months old and we just had our yard re-done with a new patio, built in firepit, and we planned to spend more time outside... cooking, eating dinner, and generally enjoying our new space. I have been told that Skin-So-Soft from Avon is a good repellent... i found it really greasy, though I think they've improved on it... I've also heard a dryer sheet tied to like a belt loop or stuffed in a pocket half hanging out, is supposed to be helpful. In the end, we didn't want to take any chances with West Nile Virus, as there had been reported cases locally... the doc gave us the OK to use OFF with Deet, BUT, she said don't spray it on their skin... put them in long sleeves and pants if possible... and spray it on their clothes. Or we would spray it on our hands, and wipe it on his clothes and then wash our hands. Deet does penetrate the skin, but... it's highly effective so we protect him from the danger of deet as best we can and make sure it's use is limited. Hopefully some of the other mom's can give you suggestions on something that is safer and natural. I just went with the doc's suggestions because we wanted to ensure protection, without poisoning him.
I cook with a lot of garlic... it's essential in Italian cooking :) I think our blood is probably too pungent for their liking because neither one of us get bitten :)
Good luck!