|Children||Zipporah, Hobab, six other daugthers|
Reuel ♂ also known as Jethro, was a priest in Midian.
Reuel lived in Midian, where Moses fled to. He gave his daughter Zipporah to Moses in marriage. Reuel had some flocks which were looked after by his daugthers and by Moses.
When Moses was at Rephidim, Jethro visited him there. He saw how Moses handled the judging for the people and suggested a change. So according to Jethro's idea, Moses put people over smaller groups and only the bigger problems would be escalted to Moses. This way, he had a lot less work to do.
In Exodus 3:1 (NIV, Elberfelder) and also at other places, Moses's father in-law is called Jethro. So either Reuel died and Moses again married a daughter of the next priest or the two names are really used interchangably. I have also read (outside of the Bible), that Reuel might be Jethro's father. Apparently the word used for Reuel is one that was also used for the elder of a place or something like that. I'll leave that for later.