I think my boys were about 2 when they went into nursery. As you said it's nice for them to interact with other kids.
I was a bit unsure weather I wanted to come back to work or not. I just don't think I'm much good at being a house wife. It was really worrying me that if I was out of the work circle for a while I'd have problems getting back in. There the mortgage too. Having said all that I wouldn't work if I didn't have my mum to rely on.
16 weeks is really a joke though. The goverment are on one hand encouraging people to have kids and then encouraging mums to get back to work with tax relife but not helping us to stay at home a bit longer and give them the start they deserve.
I'm going on now and look it nearly time to go home....