I'm looking for a good set of docs or at least a guide on how to use the CGX5 thats built into MorphOS. I cant figure out how to get more screen modes made. The ones I have now just ended up working with my system. Any help would be great!

You need to find the specifics of your monitor, then from the System Prefs...

Select "Mode Edit"
Select the Monitor tab in that prefs window.
See if there is a matching monitor in the list. If not, you'll have to enter the Horizontal Frequency, Verticle Frequency, and Bandwith by hand. Also define a new name if it isn't already in the list. (I believe you have to actually hit the enter key when inputing values.)

Select "Apply", then save. You will likely have to reboot, but you should then be able to define new screenmodes in the same "ModeEdit" part of preferences (This time using the "modes" tab.).

Yup I've done all that and they never seem to stick. I just got a new monitor and the bandwidth isnt listed in the manual. When I wrote to the support line they told me this isnt a needed value on VGA type monitor and only on RGB monitors. So I looked in the list and it seems 135 is the average for a 17" monitor. Any guess at what a Gateway EV700 has for its actual bandwith setting?

Actually it's only 70MHz

You can find all the details Here.

Google is your friend