Hey Calagent,
I recently made the switch from residential to commercial as well - you're right it's a totally different animal.
Here are some books I found helpful:
"How To Succeed In Commercial Real Estate" - John Bowman
"The Commercial Lease Guidebook" -Thomas Mitchell
"The Complete Guide To Real Estate Finance for Investment Properties" - Steve Berges
Also, here's a link to a site with some basic commercial re terms:
http://www.officespace.com/Terms.cfmGood luck in your new endeavor...