Help with a job interview?

after a year and a half and literally dozens of job applications, iv finally got a job interview. now my problem: its on thursday and i just realized im totally and utterly unprepared for it and i have no idea what to do. can you give me some tips for a successful interview? the do's and dont's? what to bring, what to ask, etc.? I really could use this job. all help is greatly appreciated. links too will be of great hlp.