Welcome,
I'd also ask what area of the city you will be working in, because that point from our fine moderator brings up an important question, will your company be providing you a car?
I do know there is a Gold's Gym on the NE side of Polanco on Homero, but not sure of a kid's club in there,
..:: GOLD'S GYM POLANCO ::..
Australia's embassy (located on Ruben Dario) and many other countries have their embassies in this area.
There is also a Superama grocery store on Horacio that just reopened its doors after a fire about 2 years ago, new and improved. There area also a few shopping malls in the area and perhaps the best dining opportunities in one area. There are other grocery stores in the area, including an enormous (even by American standards) WalMart just north of Polanco off the Periferico going northbound, practically directly across from the Hipodromo de Las Americas horsetrack.
Offhand, I know of at least 2 malls in Polanco.
The kids actually should like Dave and Buster's which is in Polanco on Homero just a bit to the east of Gold's Gym. My American cousin and I took our nephews there many times,
Dave & Busters
Polanco is one of the safest areas as it comes. There is a regular police presence there because there are hotels frequented by largely business tourists. Also expect to see federal police forces in the area.
It can be expensive as far as rent. I know of other areas that are to the west of there like Interlomas, Santa Fe, but a lot of those landlords in those areas would be reluctant to rent out for just 6 months, not that it's impossible, but Polanco might offer a better bet. There's not really any place in Polanco that I'd stay to steer clear of.
I don't know of kindergartens in the area, at least good one's that cater to English speaker. My American cousin had several friends who put young kids into the American School which is a somewhat unreasonable drive southwest of Polanco, Colegio Peterson (they have a campus close by) or even further away at the Greengates School. Peterson is especially good.
Looking at the list of schools here from the American embassy,
SCHOOLS IN MEXICO
The following would be very close to Polanco and a short drive:
Colegio Peterson, Montes Himalaya No. 615 (Kindergarten), Tel. 5540-07-99; 5520-22-13 (5-10 minute drive, nice neighborhood)
COLEGIO PETERSON
Escuela Lomas Altas, Montanas Calizas No.305, Tel. 5520-53-75 & 5202-79-86 (a few minutes further, but close to the school above).
Escuela Lomas Altas (Sunny Hills School also on the list is at same address)
Sierra Nevada School, Sierra Madre No.155, Tel. 5202-84-91, 5202-02-22, 5202-86-11
Sierra Nevada
You can actually use google earth and type in the name of the street followed by Mexico, DF and it will show you the location of the streets. If you use Homero, Mexico, DF that will show you the area of Polanco.
If you have more questions, feel free to ask.