I plan on writing a post about it at some point, I'll talk anyone's ears off about astrophotography.

I use an equatorial mount called iOptron CEM-70-EC that is computerized. I align it with the celestial north pole and then it figures everything else out from GPS and can point to where I want it to go.

Once it's there, I use a technique called "plate solving" to look up the stars in the camera view and reference them against a database of stars to find exactly where the telescope is pointing and give the mount a correction.

The equatorial nature of the mount means that it "tracks" at the rotation rate of the earth. So for every second the earth spins, the mount spins that same amount. It's not perfect though, so once it's trained on sight, I have a secondary camera, called a guide camera help out. It runs at a much higher frame rate, usually 3 second exposures, and picks out the best shaped stars to guide from. When it sees those have moved, i.e. a tracking error, it sends a correction to the mount. With the hope that it can see those stars moving pixel by pixel before the larger, longer focal length big camera can see it.

Those all keep me on target, and then I do a series of exposures, in this case I did 54, 18 for each color that are 10 minutes long each. I then "stack" those images. Stacking is a process where you rotate all the images to the same orientation and average out the pixel values for all of them, throwing out outliers. This lets me reduce noise in the final image, and given how stretched the histograms get for astrophotography, any little bit of noise ends up visible in the final image.

Let me know if you have any more questions about astrophotography! Like I said, I'll talk anyone's ears off.