NET Exam consists of three papers first & compulsory for all the students of all the subjets is the general paper. That is of general teaching aptitude, research methodology, GK, General Maths, English & reasoning. It has 60 multiple choice questions, out of which you have to attempt only 50.
Other two papers are of your subjects. second paper contains 50 multiple choice questions & third one has 75 (all to be attempted).
Generally you get three months time for preparation after filling the form, that is more than enough. For first two months, prepare every topic of the course given on the UGC website. Give just half an hour every day to prepare for general paper. in last month, solve previous years' question papers. Also read about all the four choices in questions papers. That'll help.
Keep a positive frame of mind. Be calm & believe you can do it & trust me, you can do it. All the best.