From http://stuartsierra.com/2009/09/08/run-your-own-maven-repository and http://www.javaworld.com/article/2073230/maven-repository-in-three-steps.html
Running your own Maven repository is dirt simple. All you need is a web server where you can upload files. Maven understands FTP, SCP, WebDAV, and more exotic protocols like Subversion. Here I’m going to describe the simplest one, plain old FTP. If you have a web site on a cheap, shared web host, odds are you can use FTP to manage the files on the server.
Step 1: Get Some Web Space
I’m assuming you have a web site somewhere. Lets say it’s at http://www.example.net/. Furthermore, let’s say you can publish files on this web site by uploading them to the FTP server ftp.example.net. Your FTP user name is samiam with the password greeneggs. You put the files for your web site in the directory /home/samiam/public_html on the server.
Using your favorite FTP client, create a directory named maven2 inside your web site directory (public_html in our example).
Congratulations, you just created a Maven 2 repository!
Check that you can visit http://www.example.net/maven2 in a web browser. You should see a directory listing; it’s empty, because we haven’t added any files yet.
Step 2: Configure Your Project Deployment
Now you’re ready to deploy a project to your Maven repository. If you’ve been following along with my Maven blog posts, you know that each Maven project has a project description file named pom.xml.
Open up your awesome software project and edit the pom.xml file. You’re going to add two new sections, ending up with a file that looks like this:
<name>The Awesome Library</name>
The <extensions> section loads the Maven plugin that handles FTP uploads. The <distributionManagement> section tells Maven where to publish the project. Here we specified a <url> with the full URL path to our maven2 directory. The <id> tag in the <repository> is a name that you choose — just remember it for the next step.
Step 3: Configure Your Server Credentials
Remember that the pom.xml will be part of the public distribution of your project. It’s OK to put the name of the FTP server there, but you wouldn’t want to include private information like your user name and password. Those go in a special Maven configuration file calledsettings.xml that you keep private.
You can find settings.xml in your personal Maven cache directory. On Unix-like systems, it should be at ~/.m2/settings.xml. You may have to create the file if it doesn’t already exist. Here’s what it should contain:
The <id> is the same as in our pom.xml. The user name and password are the credentials for your FTP server.
Step 4: Deploy!
Now all you have to do is run this command in your project directory:
Maven builds your project and uploads it to your public repository.
Step 5: Use in another project
Now everything should work, just make sure that the repository is accessible from the browser. Try to go to this URL: http://dom-ain.org/maven2/org/dom-ain/xxxLib/0.0.4 -- the browser is supposed to list all JARs (you library JAR, sources and javadoc) along with their checksums. That's it, now you have your own Maven2 repository that can be referenced from other Maven2 projects. The reference to your repo in pom.xml will look like:
The dependency (a reference) to your library will look like:
Take a look with your web browser at http://www.example.net/maven2/net/example/awesome/1.0-SNAPSHOT and you’ll see the JAR and POM files there.