Sail uses Maven to compile, package, and deploy its projects. Maven uses a system of repositories to find the dependencies of projects. Inorder to add a new jar to a project you need to add it to a maven repository, and then reference it in that repository.
First the check to see if the jar is already in one of the maven repositories used by the project your are working on.
These repositories are defined in the pom.xml file, or in a referenced parent pom.xml.
TODO: describe how to find these repositories in the pom and the parent poms, describe how to search the repositories.
If the jar file is in the repository then skip ahead.
If the jar file is not in a repository then you need to "deploy" it to one:
Deploying a new maven jar
and then come back and finish up on this page.
Once the jar is in a maven repository you need to add a reference to that jar in your projects pom.xml.
This reference will included at least the artifactId, groupId, and versionId of the jar.
