For understand Linux requires understanding its Unix heritage (1974). A multi-user time sharing OS developed as an experiment as much as anything, including in 1980 when DARPA chose Berkeley Unix as a platform for TCP/IP development (src) and its name was a snub to Multics (1965), at the time when competing Operating Systems included VMS (1975).
So I would recommend Unix System Administration Handbook, (3rd edition 2000), or Unix and Linux System Administration Handbook (4th edition, June 2010, estimate) by Evi Nemeth et all. Another popular text is Essential System Administration, 3rd ed. by Æleen Frisch, and Practical Unix & Internet Security. Browse the UGU - Unix Guru Universe, including their section for beginners. Older issues of ;login:, the magazine published by Usenix are available online, and make for educational reading.
I'd suggest converting one of your primary systems that you use daily to Linux, and retaining Windows running in a VM, whether via VirtualBox, VMware, or whatever. This will force you to prefer the Linux environment for daily activities while retaining access to Windows-only applications. The only thing this approach doesn't work well for is 3D graphics or games, often acceptable in a work environment.
I'd suggest a more plain GNU/Linux distribution, such as Debian or Slackware. They both have been around for a long time, and both have established user community for support via forums or mailing lists. If there is an active Linux User Group in your area, join. One goal should be to re-compile the Linux kernel at least once, even if it is just as a learning exercise. (Older kernel series such as 2.2 and 2.4 are smaller if compiling the 2.6 series is taking too long, you can run / install them in a virtual machine)
It might be educational to read some of the key FSF / GNU philosophy essays such as What is Free Software?, Why Software Should Not Have Owners, The Right to Read, and know about the various FSF campaigns. These with some of Eric S. Raymond's essays, including The Cathedral and the Bazaar give you insight to understanding the Free Software / Open Source movement, which is critical to understanding its success, and how the community of developers and users thinks and tries to act.
I hope that gives you a path to approach learning and embracing Linux / Unix more in your computing life.