I'm not really sure as to what can be said for this timeless classic mockery of 1930s horror films. The only concern I have for showing this movie to my own children is simply that they won't get it. Some of the jokes are pretty easy to figure out, but if you're not acquainted with Boris Karloff or Bela Lugosi, this movie won't be as funny. Chances are, your kids will not be familiar with Irving Berlin's "Puttin' On The Ritz", parodied by Wilder and Boyle.
As far as I'm concerned, what sexual innuendos exist will likely go over their head (as first seeing this when I myself was 8 years old, I didn't get them either). If you're familiar with Mel Brooks' films, this film is very mild by comparison to Blazing Saddles, Robin Hood: Men In Tights, or even Spaceballs, for that matter.
It's rated PG and if you've read what Common Sense Media has to say about it, there's really not much else that I can add.