Would also suggest you do a quick read-up on aircraft identification, different types. You can find some good open source stuff on that with a search.
Also take a look at why kind of aircraft are most common at your base, that will narrow down what you really need to learn. Good for daytime, not so good at night but if you study pics close you might notice some differences in the where the lights would be at night…sometimes useful.
Get a pair of good binoculars too if you don't have some. Keep 'em handy.