Joint Federal Travel Regulation (JFTR): http://www.defensetravel.dod.mil/site/travelreg.cfm
Ask the Dod a Travel Question: http://www.defensetravel.dod.mil/site/pdcQuestion.cfm
Department of Defense Financial Management Regulation (DoD FMR): http://comptroller.defense.gov/fmr
Dislocation Allowance Rates (DLA): http://www.defensetravel.dod.mil/site/otherratesDLA.cfm
Mileage Rates: http://www.defensetravel.dod.mil/site/otherratesMile.cfm
Per Diem Rate Information: http://www.defensetravel.dod.mil/site/perdiem.cfm
Defense Table of Official Distances: https://dtod.sddc.army.mil/
Basic Allowance for Housing Rates (BAH): http://www.defensetravel.dod.mil/site/bahCalc.cfm
Personal Procurement Move (PPM, DITY for us old timers): www.move.mil