This is a new distribution currently in beta test. I have not run this but am on the developer's list. It seems to be progressing rapidly toward a professional-quality distribution. It also appears that Debian will be adopted as the official Linux distribution of the Free Software Foundation. In structure Debian is much like Slackware, but the level of effort going into it is going to make it a very clean product.
This is a professional-quality Linux distribution. It is currently being distributed in Holland with U.S. distribution planned in the near future. Again, I have not worked with this distribution, but it is being developed by a new company, ARIS, as a commercial-quality product.
That depends on your needs and what equipment you have. If you have a CD-ROM drive, buying Linux on a CD is a good choice. A CD can hold over 600MB of files, and most of the CD distributions have hundreds of megabytes on them. The low price tag (less than $50) makes a CD an inexpensive way to get the information.
If you don't have a CD-ROM drive, but you do have Internet access, downloading the files from one of the ftp sites is an alternative.
If you don't have Internet access, try looking around on local bulletin board systems. Hundreds of them offer Linux distributions. Or contact your local Unix (or Linux) user's group. Many of them know people who will make a copy of one of the distributions for you if you supply the disks.
If all else fails, there are people who copy distributions to floppy disks and sell them. Costs are generally around $2/disk.
There is a manual called Linux Installation and Getting Started, written by Matt Welsh, that I highly recommend (see the review in LJ #1, page 10). This runs about 200 pages and offers answers to many of the common questions about getting your Linux system up and running. It is available for ftp access on many of the Internet sites that have Linux distributions. It's also available on paper, comb bound from SSC.
In conclusion, if you have been thinking about Linux, take the plunge. It works. It's a real operating system, useful both to help you learn about Unix-like systems and to use for real projects.