Welcome! I think that if the hosts themselves have children it is a lot easier because your kids have instant playmates and the house is kidfriendly (hopefully nothing expensive to break stored where kids can get to it, hazzardous items kept locked or stored in high cabinets, etc). As for traveling with the dog, I would suggest checking with each surfer, because that varies... Many people have pets but won't necessarily welcome a visiting dog, others will. And others don't have pets and don't mind pets. Read their profile and ask them...
I think that staying in a family home with kids is almost more natural for the kids than a hotel, because they will have many of the things they are used to at home. When I travel with my 3 year old, I take her blanket, favorite toys and books, so that at bedtime, she feels safe and goes to sleep at ease. I hope this helps! Happy trails!
Simone