Hi kel, I had my first baby at the beginning of May and am on maternity leave trying to make contact with others in the same position too. I live near you in Tottenham, and a lot of what I'm coming across is either in or near Wood Green.
There's an excellent drop-in for 0-2s and their mums on Monday afternoons at Burghley Road Under 5s Centre, a few minutes walk from Turnpike Lane tube or the shops on Wood Green High Road.
There's another mum and baby group on Friday afternoons at Downhills Park in Tottenham, but it's popular and they can only take the first 16 groups of baby and parent.
There are also breastfeeding support groups which also function as social groups, and I would recommend the one at Woodlands Park just off Green Lanes a few minutes south east of Wood Green - however, I am having to come to terms with not breastfeeding this baby (not my choice). If I do it again I'll know where to go!
All of those are free.
The NCT holds local social events and I'm planning to go to one or two in Wood Green this week or next week.
They offer postnatal courses as well as antenatal ones, and those of us on the course I did have continued to meet up since - it being a postnatal class means that we're all still off work on maternity leave, and looking to get out and meet others in the same position, whereas I didn't really feel sociable enough to have done that when I was pregnant. My course cost £60 for 6 weeks and was actually over beyond Muswell Hill towards East Finchley, but I know that there was another course that was free (with some council funding) in Wood Green - I met someone who did that one.
Presumably you will have some postnatal care and health service involvement with your baby when he or she's born, and that will be local even though your baby is being born somewhere else? Ask your health visitor about local groups/courses/activities.
My local library has posters advertising various activities.
If you'd like to meet up at a cafe, or at one of the drop ins, you're welcome to email me on elkiedee @ yahoo dot co dot uk