Common:
* Jack-o'-lantern
* Jackknife
Less Common:
* Jackdaw (a type of bird)
* Jackpot
* Jackhammer
* Jackrabbit
More Creative:
* Jack-in-the-box
* Jack-of-all-trades
* Jack-a-doodle (a slang term for a rooster's crow)
Let me know if you want more examples or have a specific type of compound word in mind!