You may ask the librarian on duty at the reference desk for assistance. The direct line is 914 606-6960. There is always a librarian on duty during library hours.
I am also available to help you. I can be reached at email@example.com. My direct line is 914-606-6629, and my office is #119 on the main floor of the library. Please feel free to contact me to make an in-person appointment.
For real-time IM, use the live IM box from the homepage of the library website.