Before you "host" your module on a server for others to download, it would be wise to test it out yourself.
This blog describes how you can test your update center module locally on your GlassFish container through the updatetool client. Hopefully you already know how to create and package your update center module.
Here's what you do to "host" the module on your local running instance of...
To try GlassFish Update Center, install GlassFish V2 (screencast). Then go to install-root/glassfish/updatecenter/bin and invoke updatetool (or updatetool.bat). You'll see a list of addon modules available for installation.
But what's an addon and how do you create one?
An addon is a companion product or runtime component installed on top of Sun Java System Application Server.