Hello Freddiemum!
I live just outside Crouch End and moved to the area more by accident than design tbh (and years before I had children). It's a reasonably quiet place, liberal/leftie, and a pretty affluent area. The East of the borough is in contrast rather deprived (but still has lots going for it imo).
Good connections to central London (Turnpike Lane tube - 10/15 mins to Kings Cross, Hornsey BR station to Moorgate in 20 mins)
Crouch End has lots of attractions for families, some of which are mentioned on this thread. But basically -
Priory Park - decent play area, cafe and a building to hire for parties
Alexandra Palace - huge area to go for walks, Farmer's Market, ice rink, shows and exhibitions at the Palace itself
Queen's Wood and Highgate Wood - great places for walking etc (easy to forget you're not in London)
Finsbury Park - revamped play area and cafe
Park Road - swimming pool
Crouch End itself has lots of cafes and restaurants which are family-friendly. Also a couple of toy and bookshops. There are also plenty of organised activities for parents and children of all ages, including Hornsey Library. Also has a big M&S food hall . You will also see quite a lot of familiar TV bods in the area!
It's also within easy reach of Wood Green High Road and also Brent Cross and Ikea aren't too far away.
The downside is the outrageous house prices and the competition for places at the better schools.
There's loads more I could write tbh - perhaps if you have some questions we could try to be more specific in our help!