We use a homeopathic called Ledum. I swear I should go on the road selling this stuff the way I am always raving about it on MDC!! lol
Anyway, it is awesome. It shrinks the bites down and makes them not itch. I've never taken it myself as I don't react very much to mosquito bites but dh & dd take it alot. I highly recommend it.

Also, there is a homeopathic ointment called Sting Stop that works pretty well if you get it on the bites pretty quickly after being bitten. Like when you come inside for the evening apply a bunch of Sting Stop.
I don't really like to use Benadryl on dd. It's a histamine blocker.
As for keeping the skeeters at bay, geraniums & marigolds work if you plant lots around the area where you are outside. And we burn lots of Citronella candles. When we're out in the meadow we use the toxic stuff but not on dd's skin. A little on her clothes helps quite a bit.
Hope this helps!