If you use maven for your project, it's very easy to start using Hibernate Spatial.
First, add the Hibernate Spatial and GeoTools repositories to you pom.xml
...
<repositories>
<repository>
<id>OSGEO GeoTools repo</id>
<url>http://download.osgeo.org/webdav/geotools</url>
</repository>
<repository>
<id>Hibernate Spatial repo</id>
<url>http://www.hibernatespatial.org/repository</url>
</repository>
</repositories>
...
Secondly, add the Hibernate Spatial Provider as a dependency. E.g., when using Postgis/Postgresql, add the hibernate-spatial-postgis artifact. Other possibilities are: hibernate-spatial-oracle, or hibernate-spatial-mysql
...
<dependencies>
...
<dependency>
<groupId>org.hibernatespatial</groupId>
<artifactId>hibernate-spatial-postgis</artifactId>
<version>1.0</version>
</dependency>
...
</dependencies>
...
Maven will now transitively resolve the dependencies to JTS, Hibernate and Hibernate Spatial (core module). Now you're good to go.