These are quite easy probably:

1. I run Suse distro. I'm curious about the startup files. Could someone explain first of all where I should set environment variables (system wide and per user)? Second how can I then make the changes to the files happen without rebooting? And third maybe please give me a rundown of the different files (most necessary ones that is), when they are read and what they are used for (include Suse Specific files if possible)?

2. I'm thinking of learning to program QT, in the context of this simulation app I'm developing. So firstly, does the free QT support openGL? Will I be able to switch the app into 'full-screen' openGL mode?

well thanks in advance.

Rich.

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I'm really starting to like Linux, haven't booted windows for over a month

Hi,
Environment variables can be set in .profile file present in the home directory of every user. you can make effect to these settings by just logging off and logging back in. However these variables can be set temporarily only for the current session using
export ENVIRONMENTVARIABLENAME=value
eg: export DISPLAY=x.x.x.x:0
printenv command displays the environment variables set on you system.
The most important config file are ones present in /etc (allconfig files eg: /etc/services /etc/sysconfig/network/ifcfg-etho , ifcfg-eth1, ifcfg-lo (used to bring up network interfaces) , etc and other files under /proc which are read at boot time. There are other important files also.

hope this serves your purpose.

boby