This depends on a lot of things. Do you want this server to be up all the time, or just when you're playing? Is it for a LAN party? Will it just be for your friends?
Clicking "Create Server" in Tremulous will start a temporary server that will only be up as long as you're playing. This is good for LAN parties and temporary servers when you invite your friends to play. If you set "dedicated" to "Internet", your server will be visible on the Master Server List.
There's a separate program called tremded.exe in C:\Program Files\Tremulous. This program will run a Tremulous server WITHOUT also running the game. In general parlance, this is what it means to run a "dedicated" server. It generally means that you are 1) ONLY using this computer to run the server, and 2) NOT also playing Tremulous on the same computer that is running the server.
You can use the basic tremded.exe program that came with Tremulous. However, if you want to have more administrative powers, or if you want some bugs fixed, you might try installing TJW's server files. And if you want to add LOTS more features to gameplay, try installing Risujin's Balance-Lite mod.
Information about all of that can be found in the thread stickied at the top of the "Mods" section, entitled "How to set up TJW's Server in Windows" or something like that.
Also, there's a button up at the top of the page titled "search", which allows you to search the forums for keywords like "server", "master list", and "dedicated" (to suggest a few). This topic has been discussed on this forum about 1000 times before. I suggest you use search to learn what you can from those threads BEFORE you ask new questions. If you've already done this, I apologize, but you should probably have said so.
