If you want AFV (or any ships/weapons) recognition Jane's guides are always a good place to start, but honestly I think you can get a lot more out of simply searching online. You'll get much better images and more diverse and detailed information--at least from civvie side. The inevitable question is "I don't know much about AFV, where do I start?"
Google the various types of AFV's, like Tanks, IFVs, APC's, etc. (heck even try googling AFV!). Wikipedia is an excellent baseline of information and images for this. After getting a rough idea of the different types and roles of AFVs start doing some searches on various army/armed forces. Again Wikipedia pages generally have a good amount of basic information and almost every page will have a current equipment/vehicle listing, link to one or links to other sources. These pages will provide a rough idea of how many vehicles, the various types and--the best part--a plethora of images. After immersing yourself in the various armies of the world (start off with the "big" players, i.e. USA, UK, FRANCE, GERMANY, RUSSIA, CHINA, to get a decent coverage of the majority of AFVs out there... though you'll be surprised where some excellent vehicles come from) you'll get a rough idea of what's more common in the various inventories.
At this point you'll likely be able to start posing questions to yourself "what's the most prolific tank in the world?" or "How many IFVs does Germany have compared to France or Poland ;D". A lot of these "I wonder/what if" questions, with subsequent google searches, will provide you a surprising amount of literature and images... A hell of a lot more than any single book volume can provide.
I'll admit I still have several copies of Jane's and various military encyclopedias, but I'd stick with the plan above... You'll save a lot more money and get more up to date info and images that way. After a while you'll be able to find out which book has the best info anyway using the same practices you did to immerse yourself in AFV 8)