I may be going out on a limb here, but I would have to say that there is no substitute for actual experience!
Get along to your local roaster and ask for a run-down, or enrol in an accredited coffee course.
Also, if you have your own espresso machine and grinder at home (or one to play with at work, if you are lucky!) go out and buy fresh beans, both single origin and blends, then experiment by running them through your machine.
If, after that, you have further technical questions about certain varieties, or the use of the espresso machine, then check here again for answers!
Hope this has helped!