Please help!

I have been using Vuze and Transmission for torrents for ages and they work great, however a friend is now using Newsgroups and NZB file downloads with unreal speeds. i googled it and found mac offer things like Unison and SabNZB, i downloaded Sab but just have no clue how to download anything or work the things! Ive tried getting a couple of HD films (10GB+) but i have no idea how to get any NZB downloads to run in these programs. I have tried via merlins portal and NZBRus??

Can anyone talk me through exactly what to do here?

Thanks :-)