With my son, we were out socially at about a month. We were out for walks and such after about 2 weeks. But that was summer in California - the weather was very nice.
This time around, I'm taking my time in getting her out. I'll probably wait 6 weeks, which is when my Mom and brother are coming to visit from out of town. DD is 3 weeks old now and really small - she barely fits properly in her bucket seat. She's only left the house twice for doctor visits and only met a few neighbours who have come to visit us.
But I have it easier this time, my MIL lives with us now, so its easy for me to leave her with a bottle of EBM for a couple of hours while I take the toddler out. I would go mad if I was trapped at home with her and the toddler all day every day.