Bail Bond missions are only available for Trevor. After finishing his first mission, "Mr. Philips," make your way to the orange question mark icon on the map in Grapeseed. This will lead you to Maude, who will regularly send you emails of Bail Bond targets with their last know location.
The first Bail Bond mission you receive will task you with capturing Ralph Ostrowski, who will be located in the middle of the Davis Quartz Quarry. This area is located just South-East of Trevor’s safehouse. Once you arrive at the quarry, head on through the entrance and continue straight on. A set of train tracks should be on your left and you'll then come to a fork in the road; go right. Make another right at the next fork in the road and proceed up the hill.
You will now be positioned at the top of the quarry where the road will spiral down into the center. This is where the Bail Bond target is located. Make your way down there and Ralph will jump into his vehicle and begin drive away. Shoot out his tires to immobilize his vehicle and pull him out of the car. Now get back into your own vehicle with him and return to Maude for your achievement.
If you have missed your chance in obtaining this achievement on the first Bail Bond target, do not worry, there are a few more targets Maude sends you throughout the game. If you need help locating a Bail Bond target, be sure to check out THIS THREAD for a good map of each target's location.