UNIX: BSD: Fast, reliable, secure, free/OS FreeBSD = Popular all-rounder, when beginning BSD start here. NetBSD = Portable (runs on a lot of platforms, including a toaster) OpenBSD = Security above anything else.
Solaris: Solid for typical tasks, optimized on SPARC, fast, reliable, secure. Windows Server 2008: Necessary for .NET development Linux: Easy, Ubiquitous, hosting companies, companies you work for & school, Resources (software/documentation)
Linux basics: History: Linux Kernel (Linus Torvalds) and GNU project (Richard Stallman). Distros: Ubuntu, Fedora (Redhat), Suse, Debian, Slackware, Gentoo CLI (command line interface) Shell: Bash (bourne, c shell, etc) GUI (graphical user interface) X window system popular window managers: Gnome, KDE, Xfce, CLI Revisited Basic commands: man, cd, ls, cp, mv, mkdir, rm, find, which Permissions: chmod Editors: Vim/vi, Emacs, pico/nano Advanced: (regex) grep, sed, awk Software: package Managers Server Stuff: ssh (headless server), Putty on windows scp, cron, wget, tar