I discovered a decent site called Single Parent Travel at www.singleparenttravel.net
Lot's of good tips for traveling with the kids---single parent or not.
They have a decent newsletter you can sign up for.

They also organize trips for single parents as well that look pretty
cool--Jamaica, Turks & Caicos, cruises, Dude Ranches, etc. Pricing
looks decent.

There is a forum that seems to be growing at www.travelswithfred.com/forums
(it is shared with their sister company a travel agency but it does
not seem like you need to buy travel from them)