We just moved from the US a few weeks ago- you will love it here!
We are living in corporate housing in the Mid-Levels not far from Caine Rd., but will be moving to our new apartment at the Bel-Air in Pokfulam next week. If you have young children and want quiet and space, I would definitely NOT recommend the Mid-Levels. The Mid-Levels are quite expensive and noisy and the pollution is very bad. I would suggest you consider (if you haven't already visited HK yet) taking a look at some of the nice areas on the southside of the island. The commute to Central (assuming you or your husband will work in Central) is only 20 or 30 minutes and you will find more space, quiet, nice buildings with lots of facilities for kids (playgrounds- indoor and outdoor, pools- indoor and outdoor, etc.) I would suggest you look at places in Repulse Bay, Tai Tam, Stanley, and Pokfulam. All of these places are very popular with expats and families, so you will find a very welcoming community of friends.
There are many great preschools on the southside too. I visited the Woodlands school at Repulse Bay (there are two in Repulse Bay, one is Montessori and the other is traditional). I really like the traditional one and will submit my application soon since there is a waitlist for the playgroup there (my son is only 19 mths.)
PM me if you want to talk more about all this. I am sure others will respond too. Best wishes on your move!
Kendal