Hello, this is my first tutorial on this forums, please don't be mean or something if I did something wrong.
Why I made this tutorial? because many peoples have asked me how to make a server on GPP since there is no tutorial.
Lets begin.
1) First of all get these files first before you do anything,
Download in attachment.
Note: Change the extension of .PK3 of the attachment to .ZIP.2) Go to:
For XP: C:\Documents and Settings\<username>\Application Data\Tremulous\GPP
For Vista/7: C:\Users\<username>\AppData\Roaming\Tremulous\GPP
Put the vm files (in the zip file that you just downloaded) in your GPP folder that I listed above.
3) Now put the server.cfg (in the zip file that you just downloaded) in C:\Program Files\Tremulous\gpp (default path), server.cfg is a file where your server configurations is in it, just change it to your preferences.
Put also your admin.dat in:
For XP: C:\Documents and Settings\<username>\Application Data\Tremulous\GPP
For Vista/7: C:\Users\<username>\AppData\Roaming\Tremulous\GPP
You may replace it, just do it and configure the levels of the admins to your preferences.
Put now your tremserver.bat in C:\Program Files\Tremulous.
4) Now it's time to portforward, this is the hardest part.
Go to Start --> Run --> type in: cmd then you type in the cmd: 'ipconfig /all' now you see Standard Gateway: 192.168.*.* (* means your numbers) type that standard gateway in your browser address and login (most of the time it's:
Username: admin, password: admin)
Now you see this, I have this site, the site is for you different because maybe you have another router.

Now find your portforward stuff, I don't know where it is on your router, mostly it is: Gaming or Application Forwarding, or Virtual Server, just when you see something like: Name, Port begin, Port End, LAN.
Now type in as name: Tremulous (or whatever you like)
Type in as Port Begin: 32123
Type in as Port End: 32123
Type in as your LAN: (see cmd ipconfig/all and look at 'Address or LAN' (most of time it is: 192.168.*.***))
Now apply and you are done with portforwarding.
You can also check at:
http://canyouseeme.org/ if your port is open.
5) Now start tremserver.bat up and hopely you get this:

If everything looks almost same as this you server is finally up.
FAQ:Question: HELP I can't see my server in the list, but everyone does!
Answer: Yes sometimes your computer doesn't show your server. Just add "yourip:32123" in your favorites, without quotes of course and you can see your server in the favorites.
Question: Why can no one join my server or see it?
Answer: Check your portforwarding, maybe you did something wrong, make sure the ports are 32123 and add firewall exception if needed (or put your firewall off -Not Recommended-)
BTW: I put the files also in attachment, just change the extension from PK3 to ZIP, since ZIP is not valid extension here

If there is any question or any feedback about this tutorial, just post it here and I will answer the questions.