Krillin
Krillin was introduced in a episode of Dragon Ball when they were  in a tournament (Tenkaichi Budoukai).  Krillin is a Buddhist monk, he also trained with Master Roshi.  He is married to android #18 and has a daughter named Marron.
Here are his fights
Bactarian-21 Tenkaichi Budoukai-won
Jackie Chun-21 TenkaichiBudoukai-lost
Chaozu-22 Tenkaichi Budoukai-won
Goku-22 Tenkaichi Budoukai-lost
Cymbol-Died
Piccolo-23 Tenkaichi Budoukai-lost
The Pendulum Room Saiya-Died
Saibamen-won
Nappa-lost
Vegita-lost
Guldo-lost
Recoom-lost
Goku-couldn't fight him
Freeza-lost
Android 17-lost
Punter-25 Tenkaici Budoukai-won
Darbura-got turned to stone
Ginue Force-he got beat up real bad

Gohan
Gohan is the son of goku (kakarrot) his power level can rise very high based on his emotions.  He his a hybrid part saiyan part human.
Fights:
Raditz-he was kicking raditz along until his power level dropped and he got kicked far.
Vegita-lost
Ginue force-lost
one of Frieza's goons-won
Piccolo-lost