The Curve is between a 3.0 and 3.2 except for your small section which can't exceed a 3.3. See this website for more information. http://law.hofstra.edu/StudentLife/StudentAffairs/Handbook/stuhb_chapter_06.html#acad_reg
As for prepping, I did not do anything over summer. I just came in with my basic legal information that i have gained through the years but nothing in particular. If you do not have a difficult time understanding concepts, then I don't think you need to prep. If it takes you a while, then you might want to get a head start. However, I will caution those that want to go ahead, that you do not know what your teacher will be covering in the class or which semester if it is a year long class, so you have the possibility of learning something that you will not need. If you are really bored, maybe read one of those general law school books like getting to maybe which my friend recommended but i did not read. I also do not wish I did, because I did very well without prepping.
Any other questions?