If ever you are looking for generalized information, you can always look at learning.intersystems.com as well as the documentation (docs.intersystems.com). There's a lot of good videos there that you can use to help get going. If you have any specific questions there are plenty of us who would be happy to answer them.
Take a look at this documentation. It goes in to a lot of detail with some useful diagrams.
*edit*
There is also this useful Mirroring 101 forum post.
If ever you are looking for generalized information, you can always look at learning.intersystems.com as well as the documentation (docs.intersystems.com). There's a lot of good videos there that you can use to help get going. If you have any specific questions there are plenty of us who would be happy to answer them.
I agree with the previous answers as a good starting point. If you get past there and want to set up a mirror, take a look at this post.