http://www.cs.hut.fi/ssh/: follow links to download ssh files to be unpacked and compiled. I used ssh v1.2.26, the high-water mark of v1. v2 differs in internal code and licensing.
http://www.replay.com/redhat/ssh.html: download ssh in RPM form, installable pre-compiled binaries. Easier to install, but you forego making certain configuration choices that can be set only at compile time.
http://www.net.lut.ac.uk/psst/: links among other things. MS machines need their own client to interact with sshd on a Linux server.
http://www.uni-karlsruhe.de/~ig25/ssh-faq/: ssh (secure shell) FAQ, frequently asked questions.
http://www.tac.nyc.ny.us/~kim/ssh/: getting started with ssh.
man pages for ssh, sshd, ssh-keygen and README.SSH.
http://www.courtesan.com/sudo: sudo home page, to download sudo.
ftp://ftp.vein.hu/ssa/contrib/mag/pty-redir-0.1.tar.gz: source of pty-redir, needed for the VPN.
http://oac3.hsc.uth.tmc.edu/staff/snewton/tcp-tutorial/: “Introduction to the Internet Protocols” I don't remember the last time I got this much more than my money's worth.
comp.security.ssh, comp.os.linux.networking: newsgroups
The Linux Network, Fred Butzen and Christopher Hilton, IDG Books Worldwide, Inc., 1998.
Practical Unix and Internet Security, Simson Garfinkel and Gene Spafford, O'Reilly & Associates, Inc., 1996.
Linux Network Toolkit, Paul G. Sery, IDG Books Worldwide, Inc., 1998.
“Post-Installation Security Procedures”, Eddie Harari, Linux Journal, December 1999.
“Transparent Firewalling”, Federico and Christian Pellegrin, “Strictly On-Line”, Linux Journal, December, 1999.