Baby groups are great. They're great for you and great for baby.
You don't have to spend loads, we go to a couple at our local library which are free. Then you've got the good old sure start centres and family centres... loads goes on there.
Then you've always got net mum's www.netmums.com they have lots of information and lists of groups local to you.
My favourite group is The Nest www.horizonchurchsutton.org/the-nest I learnt about it through a friend (along with other mum's it also a good way of finding out what's going on).
Would definitely say to anyone living in Sutton are come along, here's a quick review: