How do i find the server for Setting up Exchange ActiveSync

I have been trying to setup my work e-mail on the 4s, and it keeps prompting me to fill in the "server" field. I have looked into my e-mails options and tried most of the numbers that look like they could be related to no success. I am very unfamiliar with apples interface as this is my first apple product. Any help explaining where and what information i am looking for is greatly appreciated.