A few months back I started using maven for a project, and since then my appreciation for this tool has been on the rise as I discover various feature and new plugins. Maven help out with software development process as well with design. Following are some of the benefits I have experienced.
Maven adds structure to your code repository. There is a place to put different artifacts (java source, properties files etc, JUnit test cases), this structure brings consistency to how code is organized in version control system.
Maven promotes modular design thru its dependency management feature. You can break up you project into different modules, and then build other modules on top of other modules. Maven can bring these modules together at build time. For example you could separate out DAO/Data model code create a maven module, then create another maven module for business logic which uses DAO/Data module, maven lets you specify the dependencies. This way you are maintaining a modular code and this will help you avoid mix up between your Data model class and business classes, lower layer modules are usable in multiple project if you need them.
Maven also helps you manage dependencies on 3rd party modules. you don't have to manually download tonnes of 3rd part jars, instead provide minimum information (artifactId, groupId, version) about 3rd party components, and the associated jars will be downloaded for you, you won't have to keep track hundreds of jars coming for dozens for 3rd part components.
Another advantage of of Maven is it lets developers work with different environments like QA, development, staging, production with ease. Settings for different environments could be specified in respective properties files (for example where is QA DB ?) , and at build time simply include the property file or apply these properties to various configuration file and other resources by simply specify a profile switch as one of the maven command argument.
Maven lets you run JUnit tests associated with you project.
Maven provides command line interface, and also works very well with popular IDEs like Eclipse and Netbeans, and with automated builds tools.
A wide range of maven plugins are available to do various task like compile, packaging, generating code and lot more. For example generating axis WSDL code from existing java sources, you could create various packaging foo you projects, execute SQL script againsts database, deploy your application. These links provide plugin descriptions http://maven.apache.org/plugins/index.html, http://mojo.codehaus.org/plugins.html
When you are starting with Maven the terminologies could be daunting but once you start using it, it is a pleasant song.
