Did you burn those CDs ? well then reboot from the first CD that contains packages and start the installer.... it would walk you through the installation .... but make sure that you have a 5 GB primary partition (no logical partitions please) .... separately reserved .... then figure out how to partition your disk... and you're done.... have you installed Linux before ? otherwise this is gonna be a daunting task for you !!!
you can go through its official FAQ and Getting started guides...
Click here for BSD Manual:
*www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/index.html
Click here for FAQ:
*www.freebsd.org/doc/en_US.ISO8859-1/books/faq/index.html