labeling system

hi, i have to make some kind of labeling system for my game. every object that is clicked need to be marked, or his label or tag shown. i was thinking about the bubble over the object with the little arrow pointing towards object. i need how to draw the line (with opengl calls), also i think i would know how to draw the bubble. the thing that i dont know, or what is the best way to do it is how to control the position of the bubble and the line while the camera rotates around the object. also i would like to move bubble out of the way so it dont cover important parts of the screen. i know the topic is complicated, if somebody could share his thoughts it would be appreciated, i just need to be pointed in the right direction. thanks!