by the way you posed the question, i assume you are installing sol8 for Intel...
i can speak more so for Sparc......
simple...put in the install cd, power up the machine and do a "stop a" and then type in "boot cdrom"
and i believe the Intel is some what similar, basically Solaris will walk you through the process of getting it set up.
also, do you have a good understanding of partitions and files sytems? have you ever used any form of Unix, have you every used Solaris before, your posting didnt give much of a background of it...
good luck !!