
I had a labrador and a dalmatian when I had my son, and I had to be in hospital a week. When I was still in the hospital my husband would bring back the baby clothes (and my nighties!) and let the dogs have a good sniff at them, so they had a clue what the baby smelt like. Then when I got home at last I greeted the dogs first (what a wonderful welcome that was:) :)) and then did what the midwife told me - I put the carrycot on the floor and the dogs had a good sniff and lick at him, and then came back to me for reassurance when he squirmed and cried!
Bless them, they were wonderful. I made sure I let them come up and watch at nappy-changing, and feeds etc, so they didn't feel they were being pushed out. We'd sit on the sofa all together - all one big 'pack' together.
Bear in mind that terriers have more of a 'prey drive' with small creatures, so take care and watch how they react to the baby's crying etc. Try to keep their routine the same as much as you can, as it is very easy for them to feel jealous. I personally would have them sleeping in the kitchen, but then I like my dogs to sleep there anyway - it may be too late to try to move them now.