Check this sheet out. I just posted it on another thread, it should get you started. No need to freak out, just relax, this is supposed to be the easiest section of the test. Just do the videos (Chad's), do his quizzes, and work through the destroyer. What I did was take the "Road Maps" that are in the destroyer and..:
1st - print off an exact copy of the reactions (as it already is)
2nd - white out all the products
3rd - run off about 10 copies per Road Map
4th - go through these with a pencil and red pen
5th - at the end, any of them you miss, red mark them and study them
6th - redo over and over until you can do them with your eyes closed lol!
Maybe this sheet will help a little, but definitely do the above. It will save you time and will allow you to spend more time in the Gen Chem section doing calculations. From what I hear, 15-18/30 of the questions in the OChem section are these reactions alone.
Best of Luck To You and Happy Studying!