Google will tell you most of these things, as they are all regular and 'calculatable' events. Wolfram Alpha has a very comprehensive eclipse set-up too. Or you can simply buy a book - there are plenty of 'star guides' that include dates for eclipses and meteor showers.
Unless you have your camera hooked up to a telescope, or you have a massive lens and a motor drive, things like planetary alignments are probably not worth driving out of town for. Likewise, meteors are tricky to photograph as they are unpredictable and flash across the sky in a split second.
Eclipses and comets are somewhat more stationary, but they are few and far between.
Why limit yourself to 'events'? There's plenty in the night sky to photograph every night. The plain old moon can make spectacular photos, especially if you shoot it in its gibbous stage so you've got some shadows in the craters. Point your camera at the lower half of Orion's sword, open the shutter for 5 seconds, then take a look at the screen. You will see a glowing purple cloud: the Orion Nebula, a stellar nursery.
Shooting things that are there every night also means you get good practice for taking photos of rarer astronomical events.