Code concepts and services are generally the same. However the 2012 interface is very different. If you are interested in learning about 2012, you should download a trial copy, get familiar until you can get a good 2012 book.
I dont want to give you a specific recommendation for 2012 because I just havent found that "got to have" book as of yet. The "Introducing Windows Server 2012" is free for the Kindle, and I skimmed through the "Inside and Out" book briefly. Its OK.