With a new baby, you will want to be getting out and about, meeting other parents and babies. There are lots of classes on, such as baby yoga, baby signing and singing groups, but these can be quite expensive; yet with a bit of hunting and asking around, fun activities can be had for free.
The first port of call is the local library, many of which hold weekly ‘rhyme time’ sessions, where parents and babies can meet and sing nursery rhymes together, led by a member of staff. I also found it was great to get into the habit of regular book-borrowing, because even if you have some baby books already at home, it is good for you and for the baby to have access to a greater variety!
The health visitors are a good source of information on local activities. Ours directed me to our local family centre, which hosts a number of different baby and toddler groups weekly. Although I only went a few times, these occasions were invaluable to me in terms of getting out of the house with a newborn, and the kind members of staff will make you a cup of tea and give you a little break. The family centre also held a free baby massage group, which I really enjoyed and learned a lot from.
Not free, but pretty cheap, swimming is fun with a small baby, and some cinema networks hold showings especially for parents with babies (for example the Picturehouse network). Seize this opportunity to go and catch a film, because it won't be easier once your baby gets more active!