Hello!
You'll love NJ! There are a fair few NJ Mumsnetters (reminds me we should organise a summer NJ meet up!).
We moved from London to NJ in Sept and are really happy with the move (though my husband is from southern NJ so we have lots of friends and family around here compared to none in London! I miss getting to Ireland easily but we're only 20 mins from Newark so it was v easy when my mum visited!). We're actually in the process of buying, as we wanted to rent before fully committing. We have 2 DC (12 months and 3) and I went through the preschool thing last Nov/Dec as January is when the applications went in. For good preschools starting in Sept, it's a probably waiting list only.
I don't personally know of any preschools in Montclair but Playhouse in West Orange is fantastic and was on our list (we decided the drive was too far each way with a younger child to consider). But it is a totally lovely school and the staff and parents we met were wonderful. I'm still a little wistful about it...
I have cousins in Morristown but their DC go to the YMCA - more a daycare than a preschool. So there is a preschool programme but it's not really preschools in the way it's generally meant.
Once you pick ones you like, get on the waiting lists. Places open up and you can be nicely persistent, checking in and emphasising how much you hope your son can get in etc.. We were lucky enough to get into our top choice school (this co-op nursery school) but only our 3rd choice (2 morns a week). But by march we were bumped up to our 2nd choice (3 afternoons a week). Siblings get priority, so we won't have the same rigmarole with DC 2.
We went with co-op in order to make more friends in town. Plus I'm really taken with the idea of seeing my son during his preschool life! If childcare is an issue (it was for me, as I'm a SAHM at the mo with no local babysitter), I've been assured that other parents will help out on a reciprocal basis (and DH can take a morning off if necessary!).
Check out the local message boards eg Morristownonline) or the local Mothers & More chapter or yahoo groups or whatever you can find and post threads asking for recs & advice on preschools. People should be helpful and friendly (our local message board [[http://www.maplewoodonline.com/ maplewoodonline is a font of info and advice!).
Ask your realtor - they usually have lots of knowledge of schools (even preschools). I found our relocation liaison company kind of rubbish - they're based out of NYC so all the info was v generic. Trusty old google combined with the local town messageboards & Mumsnet were more useful.
Out of curiousity - Morristown & Montclair are v different. What is it about them that appeals? The styles of homes, the lifestyles, the vibe of each place is very different.
We considered Montclair (gorgeous town but decided the commute was too long into the city) but Morristown is too suburban and spread out for us. Also too far from the city. On the plus side, Morristown doesn't have Essex County property taxes like Montclair (we're also in Essex County and the property taxes are eye watering! But the state schools are fantastic...if you're wanting to educate privately then I'd say skip Essex County and stick with the lower taxes of Morris County!).
When looking for a place to rent, we focused mainly on Summit/Chatham/Millburn/Maplewood/South Orange (all along the same train lines out of Hoboken & Penn Station) and ended up renting in Maplewood. And we love it so much that we're going to buy a home here (well, either in Maplewood or the neighbouring town of South Orange - we view our final short list of homes tomorrow and will be putting an offer in on one!). The towns are diverse, thriving, friendly communities and we're really happy that we moved.
If you're looking to buy, the schools are zoned by address. So double check the zoning info on the relevant school board websites. Also, check out GSMLS as it has all the info that the realtors use and helps you get a sense of what's on the market (not so good for renting but invaluable for buying). You still need a realtor but it's still a useful tool.
Anyway, wherever you move to you will have a great quality of life. It's a lovely part of the world!
Sorry for the massive ramble! I've not been on MN for ages so must have had pent up posts in me 