To setup GRUB, you should have the choice when you install. All you should have to do is go through the upgrade procedure and choose GRUB instead of LILO.

The other thing you should do is make sure that all the hardware you are using is supported by Linux. Check out http://hardware.redhat.com/hcl/genpage2.cgi. This is a compatibility list which will tell you what hardware Linux supports, and what it doesn't.

I've had basically the same problem as you are having, and it turns out my video card wasn't supported. Give it a go, maybe it'll help.