On the Cornell Graduate School web site you will find all Graduate School forms, the Code of Legislation of the Graduate Faculty, information regarding student services and financial aid, and much more.
The Cornell Engineering Graduate Student Association has put together a wonderful handbook — The EGSA Handbook — that discusses not only academic issues of graduate life, but also important things like how to find housing in Ithaca, where to eat, social and recreational activities, support groups, and personal safety. Take advantage of the efforts of those industrious engineers and surf through the handbook.
Graduate Student Assistantships
Cornell's Graduate Student Assistantships policy may be dry reading, but all graduate students should at least peruse it in order to understand their legal obligations and protections. In particular, if you fail to uphold your responsibilities, the university can legally force you to repay your stipend.