Building new computer help question DUO CORE E6400

I now have a new E6400 Dual Core Conroe process along with the ASUS P5B Mother board and GEForce 7900GT 256MB Video card and 2 gig of DDR2 ram 800 MHZ memory along with a Serial ATA 160 G Seagate 7200 rpm drive and a new 500 watt Antec power supply. I put it all together as a new system and turned it on and I can't get anything to show up on the monitor, there fore I can;t update the BIOS like I need to. Any thoguhts or suggestions would be great but Ithink I need to updat eteh bios so that I can start the basic stuff and install Windows XP ect. I know enoguh to be dangerous but anythoughts would be helpful.Thanks Shayne