I am a newbie to Linux and find this thread extremely useful. I have several questions, if I may barge in.
1. It was mentioned that installing Knoppix to HD is not a godd idea for various reasons, including that it would not be very secure. Is the security problem related to Knoppix itself or to the underlying Debian? Does the less sercure comment apply to using the live CD (uninstalled) too? What exactly is meant by "less secure"? Less stable or less secure internet-wise?

2. I did not know that Mepis and Ubuntu had a more limited source of available software compared to Debian. I did download Mepis as my first distribution and it installed and worked great right out of the box - which is a great confidence booster for a newbie. My question is related to the greater range of available software for Debian. Since distributions like Mepis and Ubuntu apparenty have quite large software repositories, how important would the non-available software be to the majority of users? That is, would it be isoteric software that 99% of people would never want? I am just curious and trying to understand.

3. I intend to purchase from Linuxonline.biz and similar the Debian you suggest to try and install it. However I have a find I would like to share with other newbies. I recently borrowed from the public library a new book: 6th edition of "Linux for Dummies" which contains a DVD that contains:

Fedora Core 3 complete
Full version of Linspire 4.5.602
Live version of Linspire 4.5.602
Live version of SUSE 9.2
Full version (3 CD isos) of Mandrake 10.1
Knoppix 3.6
Xandros 2.5
OpenOffice

This is a terrific for someone like me who does not have access to broadband. It allows me to try several distributions without the hassle of downloading and gives the newbie a head start in the exploration of distributions to choose. The book costs only $29 but is an even better deal for free from the library.