The pass mark is 60%. 240 marks out of 400.
While your score report will give you your scores for each section, it's the overall score that counts. So if you are strong at kanji or reading or grammar you can make up for a weakness in listening.
Listening is worth 100 marks.
What advice I can give is:-
relax
concentrate
you don't have to understand everything but try to pull out the important info.
If you can't, give an educated guess at least.
If you can't make an educated guess, mark an answer, you might get lucky.
Unlike the other sections, in listening there is no time to go back over your answers. Answer quickly and be ready for the next question.
Ask your teacher if they have a practice exam you can borrow.
The type of questions on the test are very specific to the test.
I can't remember seeing any on the Internet. (Apart from the paid section here)
MLC has some audio resources and quizzes that might help.
http://www.mlcjapanese.co.jp/Download.htm
Japanese bookstores that sell textbooks for JLPT often carry the past papers as well.
There are also example test books written by other publishers
Offhand I can only think of the title of the Minna No Nihongo series
http://www.3anet.co.jp/english/books/te ... oukai.html
These listening tests are similar to the ones on JLPT and should be at a similar level.
Generally listening to Japanese, such as the podcasts here, helps enormously as well.
(If they wanted to add a JLPT angle to the podcast they could ask one comprehension question after the first full speed dialogue portion. They have written ones in the premium section but it's not quite the same.)