You change the boot sequence by hitting the DELETE button on the keyboard as your computer is Booting up.
This will take you to the cmos settings.
Navigate to the boot settings and you will see CDROM , Floopy, Harddrive etc listed.
Just make the CDROM the 1st, ie up the top of the list and then hit save and exit.
Then reboot your PC, it'll then look for the CDROM as your fisrt boot order, if a CD is in the CDROM it will start reading it. if not then it will boot to your next, usually the Harddrive, and start normally.
Re operating requirements, insert the Live CD and you'll soon know if there are any problems with running your O/S. A lot of hard ware is supported and doesn't need any tweaking.
Dialup internet is a little harder as most are WINMODEMS, but if you are on ADSL or Cable with an etho cable then all is well straight from the box.
If your Modem is ADSL and USB supported then may be a little prob, as Etho is better.
I'm only running an AMD 2gig, with onboard graphics /sound and 768 Mg of Ram and it is fast enough.

