Those guides by russs15 are nice with some good information. Being on a Mac, you'll have to use equivalent tools, of which there are excellent choices. I'm on OS X and I use Unison for downloading and uploading. It's very Mac like and easy to use. I love it. Hardcore usenet Mac geeks like Thoth. It's no longer being developed and has one of the worst user interfaces I've ever seen.

In binary newsgroups (like alt.binaries.starwars) you'll be running into split up RAR archives mostly along with PAR files. Use the russs15 links and google to learn about rar's and par's.

UnRarX - Joins your split RAR archives and extracts original files.

MacPAR deLuxe - With PAR files, allows you to recover incomplete, corrupt, or missing RAR's (or other types of archives and files). Will also "UnRar" archives. Great program.

You'll want to get access to usenet with a premium provider. I use Giganews. There are other choices. Your ISP probably offers limited access. But it's usually worthless, as retention times are incredibly short and many newsgroups aren't even carried.

Two years ago I didn't know anything about usenet. I saw that all of the good projects were being posted there and I wanted in. I took a while to research things from the Mac point of view and just learned as I went along. Now, I can download a full DVD5 in 2 hours. Torrents, on the other hand, are a cruel joke. If you're lucky, you might get that same DVD in 2 days, most of the time much longer. Trust me, take the time and expense to get into usenet...