IRS Publication 571:  This publication defines the IRS rules for 403(b) & 403(b)(7) Plans.  This document will define maximum limits, loans, hardship withdrawals and qualifications.   http://www.irs.gov/pub/irs-pdf/p571.pdf 

IRS Publication 590: This publication defines Traditional vs. Roth IRAs rules.  This document explains who can contribute, maximum contributions, distributions and tax implications. http://www.irs.gov/pub/irs-pdf/p590.pdf