You should be able to find all of the information you need here:
MangosWiki
On MaNGOS, the only significant change you will need to make to send your server live is in the database.
In the "realmlist" table under the realmd database, you will need to change the realm address to your external IP address. (found at What's My IP Address? Networking Tools & More )
You will also need to forward the below ports on your router, and have them point to your dedicated server computer.
And lastly you will need to edit your windows hosts file to say:
Code:
"your router IP" "your static IP" (router IP is 192.168.#.# or whatever address your router uses)
"your external IP" "your static IP" (external is found on IP websites)
This is really the only difference between a local and public server, if I am correct.
Hope this helps!
-Haith
[Edit]: Oops, forgot about your second question. I believe that at around 2000-3000 players, your MaNGOS program will start to take up around 10GB+ of ram. I can't say anything about bandwidth, but I believe the RAM numbers are somewhat accurate. (Hosting large populations takes quite a bit of power from the computer
)