You need to be PATIENT! You wont find much info on bobbers because most guys dont use bobbers to float bait with. You will however find a ton of info on fishfinders or also known as sinker slides. Boaters use either baloons or something called planer boards (for another discussion). I've used bobbers to float eels over eddies in a river with no luck, but its not something I would bother with. Although this is part of another post from Roccus about a tactic he used when blue fish were marauding. I learned from another old trixter only because I caught him red handed! while everyone else was singing the "blues" he was racking up some impressive catches on green crabs by anchoring by structure in a current and floating the crabs under a large cork bobber,I've tried it several times(using a ballon instead) with mixed results,I have caught bass,some good ones too,buy have also been skunked when i knew the bass were present but ole razor lips refused to let my eel swim un molested....but they never ate the crabs!!!!!
You can find a whole bunch of info here in the beginners clinic.
read it and it will help you on your way. You will begin to see a theme developing through some feedback. Take it all in slowly and learn, grab your gear and get out every chance you get and BE PATIENT!
The guys here know much more info than I do about this stuff.