Unable to manage music/videos on my 3g

[Sludge]

Hey hipsters... I am sure this is an easy fix, but for what ever reason I cant figure it out. I just got home with my new iphone 3g. for what ever reason I can sync my tunes to my iphone, but I can not drag and drop what I want on my phone from itunes, or can I erase a file from my phone once its there. example. I have a ton of audio books. the only way I can add them too it is to sync them all to the phone. Once they are there I can not delete one book over the other... same with videos and other audio files...

I have an Itouch as well.... I can drag, drop, remove with it no problem. I can sync them all at once... or just pick and choose what I want..

Any ideas??? thanks...