I'd say the 24mm 1.4 will be pretty good. When I did a lot of night photography I was using an 18-55 2.8-4 lens on a 1.6x crop camera such as yours and I almost always kept it at the wide end.
You might find you want even wider. The 16-35mm 2.8 zoom costs a whole lot but it adds versatility, but then it's going to make you want a full frame body to really use the wide end as a wide end.
I think Rokinon makes a 12mm f/2.0 for crop cameras, might not be of quality conducive to huge prints but for a hobby if you're willing to do some tinkering after the shot i'm sure it's fine.
It's going to be a lot of trial and error. There's a website called DarkSky that lets you see the forecasted amount of haze/light pollution/moonlight, etc that will interfere with your shot.
If you want to do star trails, look into stacking. I've used a program callled StarStax a bit on Mac, there might be a windows version or similar solution if you're on windows.
The suggestion of a remote trigger is good, but using the self-timer is also good.