As with many fields and subfields, Rasch has its own journal - the Journal of Applied Measurement, which publishes a variety of articles either using or describing how to use Rasch measurement. You can read the table of contents for JAM going back to its inaugural issue here.
But JAM isn't the only resource available for Rasch users. First off, JAM Press publishes multiple books on different aspects of Rasch measurement.
But the most useful resource by far is Rasch Measurement Transactions, which goes back to 1987 and is freely available. These are shorter articles dealing with hands on topics. If I don't know how to do something regarding Rasch, this is a great place to check. And you can always find those articles on a certain topic via Google, by setting the site to search as "rasch.org".
Finally, there is a Rasch message board, which is still active, where you can post questions (and answer them if you feel so inclined!).
As you can see, I'm a bit behind on A to Z posts. I'll be playing catch up this week!