You should always watch/listen to whatever it is I suggest here before you unleash it on your children. My standard of what is "appropriate" for kids might be very different than your own.
Basically, I'm trying to accumulate a collection of good hip-hop that is OK for kids to listen to. I'm not particularly interested in rap made specifically for kids, because, in my experience, most of that stuff, uh, sucks. In general these songs are songs made for grown-ups, but also just happen to be appropriate for children. But if I come across good tunes made specifically for or by kids, I will, of course, recommend them.
In general, I'm trying to find rap songs that are:
1. not degrading to women/LGBT folks/anyone.
2. do not have violent lyrics or images
3. are not overtly sexual
4. don't have curses
However, I make no guarantees that any of this music is squeaky clean. If there's an awesome song that is otherwise clean but has one mention of a blunt, I'll probably let it slip by. Also, and this seems especially true in older hip-hop, rappers often talk about "killing" their rival MCs. Once again, in songs where it is pretty obvious that it is a metaphorical "slaying," I'll let it go. Also, I don't know all of the street/slang terms, so if a nasty one slips by me, sorry.
I'm not very interested in "clean" versions of "dirty" songs (i.e. radio-friendly edits where they just edit out the curse words), though I may resort to these if I really like the song.
I think it's safe to say that most hip-hop (there are exceptions of course) is at the very least heteronormative and reflects the patriarchal nature of our society. Also, while there are, of course, many great female rappers, rap music is still made mostly by men. Whenever possible, I will try to emphasize great women rappers, but I'm guessing the men-to-women ratio highlighted in this thing will be skewed towards the men.
I am not on any sort of crusade to "clean" up rap music. I listen to, and love, all kinds of rap music, and it's not important to me that most rap music made for adults is inappropriate for children.
Also, I think it's important to mention race: Rap music is a musical form created by people of color and my perspective is that of a white middle-aged guy that grew up in the suburbs of Long Island (thus my undying love for PE and the Native Tongues crew). So, please keep that in mind.
Thanks for reading this long, boring thing.