If you want to start using Linux, you have to choose a distribution. A wrong choice may lead to unsuccesfull use, and disappointing results.

If you don't know what a linux distribution is, click here

The main difference between the distributions is the additional software. Unless every program is almost never distribution depended, choice of distribution is important.
If you're going to use Linux for HAM perposes, my advice will be SuSE Linux. I'm using SuSE Linux 7.1, but newer versions are allready released.
The main advantage for SuSE Linux is that they delever HAM Software with their distribution. There programs are used for: APRS, SSTV, Packet Radio, CW, QSO Logging etc.

Here is a link to SuSE Linux with most recent information.