Where will DH be working? Broadly speaking, for living you have a couple of choices (depending on where DH is based):
Southern Suburbs
Northern Suburbs
Atlantic Seaboard
False Bay Seaboard.
Southern suburbs is the traditionally "upmarket" areas - tends to have very good, and well established schools, is mostly relatively easy to get into the city from (although traffic can be bad), probably one of the safest areas to live with lots of well established homes and areas with neighbourhood watches, walls, fences etc. It will be more expensive than most other places.
Northern suburb: used to be the less affluent part of cape town (for white people during Apartheid). However, it's increasingly up and coming, with some fabulous new places/complexes etc. Beautiful beaches in Milnerton etc. Traffic into the city can be murder as the roads weren't built big enough. And it's windy - that's why the original Dutch settlers settled in the Southern Suburbs rather : it was too windy to grow crops.
Atlantic seaboard - very very posh and expensive. Lots of holiday homes. Very modern. Much fewer good schools (ironically) so your kids would have to commute. Also, there's been more crime around there lately I believe - possibly as a direct result of the sheer affluence you see there.
False Bay seaboard is south of the southern suburbs. Truly beautiful, child friendly beaches etc. But if DH is working in any of the major areas, it will be a heck of a commute for him, with lots and lots of traffic. My perception is that it's a bit more racially integrated which I like, although my PIL are probably less keen!