I was lucky as a little kid as far as my introduction to Hip Hop goes. Living in Chattanooga, TN we weren't exactly in a mecca for heads, but my older cousins always kept a lot of good stuff around me. Even though I didn't become a full fledged devotee of that ol' boom bap until my teenaged years, I got an ample earful of Doug E. Fresh, Biz Markee and Slick Rick as a child (and 2 Live Crew, don't tell my mom), cruising around with them when they'd have me. I always told myself if I had the chance to play the big brother role, I'd try to introduce the little brats to quality Hip Hop. I've been lucky enough to have younger cousins I could pass music onto, and more recently I put together a mix of tunes for a dear friend so her young son could get a taste of decent Hip Hop early. I mixed old with a little new, and basically tried to keep in mind what sort of stuff I would've liked listening to as a little kid. Since it's actually for a little kid, I did a few radio edits here and there, some for words (but not many, 'cause y'know, I kept mindful) and others for space and less obvious reasons (the static and jargon at the end of DJ Shadow's "Changeling" probably would've freaked me out a little bit).
I didn't put them in any kind of order so play them however you'd like, though if you're making a tape for a kid, I recommend Blackalicious' "Sleep" as the closer. It's a fine lullaby.
For The Kids - Hip Hop For Youngins
Bonus: Here's the Exile joint that I actually got the title of the post from.
Exile - For the Kids