Not got much experience with it, but dabbled a little bit. Was pretty simple: Click download server in the launcher, click the start server file thing(bat file I think it was) and that was it.
I copied in a save I had created in a single player enviroment. Thought that was easier than figuring out how to spawn the world on the server.
If you need more help, I just did a video search on google: "minecraft ftb server guide" and there were tons and tons of guides.