Free tutoring
The department offers free tutoring for the lower division math courses. The schedule can be found here: http://www.math.nyu.edu/degree/undergrad/tutor_schedule.html
The University Learning Center also provides free tutoring for lower division math courses. More information can be found here: http://www.nyu.edu/students/academic-services/undergraduate-advisement/academic-resource-center/tutoring-and-learning.html
Other resources
NYU Department of Mathematics: http://www.math.nyu.edu/
Department of Mathematics Courses: http://www.math.nyu.edu/courses/ug_course_descriptions.html
Department of Mathematics Course Placement: http://www.math.nyu.edu/degree/undergrad/calculus.html
Courant Institute of Mathematical Sciences: http://www.cims.nyu.edu/
New York University: http://www.nyu.edu/