see http://blog.flex-mojos.info/2008/03/29/more-them-a-hello-world/

You will need to install your datavisualization libraries like this:

mvn install:install-file -DgroupId=com.adobe.flex.sdk -DartifactId=datavisualization -Dversion=3.0.0.477 -Dpackaging=swc -Dfile=<path to flex sdk>/sdks/3.0.0/frameworks/libs/datavisualization.swc

mvn install:install-file -DgroupId=com.adobe.flex.sdk -DartifactId=datavisualization -Dversion=3.0.0.477 -Dclassifier=en_US -Dpackaging=swc -Dfile=<path to flex sdk>/sdks/3.0.0/frameworks/locale/en_US/datavisualization_rb.swc

<?xml version="1.0" encoding="UTF-8"?>
<!-- XML header, nothing new -->
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<!-- pom.xml model version -->
	<modelVersion>4.0.0</modelVersion>
<!-- Inherit from flex-mojos flex super pom
            This enable maven to compile, asdoc, ... without writing <plugins> on <build>
        -->
	<parent>
		<groupId>info.rvin.mojo</groupId>
		<artifactId>flex-super-pom</artifactId>
		<version>1.0</version>
	</parent>
<!-- this project ID -->
	<groupId>com.adobe.sample</groupId>
	<artifactId>dashboard</artifactId>
	<version>1.0-SNAPSHOT</version>
	<name>Dashboard</name>
<!-- What will be generated.
            Must be swf, swc, aswf or aswc
            swf and swc for flex
            aswf and aswc for air
        -->
	<packaging>swf</packaging>
<!-- this project doesn't follow the standard directory structure, so, need to specify where are the sources -->
<build>
	<sourceDirectory>src</sourceDirectory>
	<plugins>
		<plugin>
			<groupId>info.rvin.mojo</groupId>
			<artifactId>flex-compiler-mojo</artifactId>
			<version>1.0</version>
			<extensions>true</extensions>
			<dependencies>
				<dependency>
					<groupId>com.adobe.flex</groupId>
					<artifactId>license</artifactId>
					<version>3.0.0.477</version>
				</dependency>
			</dependencies>
			<configuration>
				<useNetwork>false</useNetwork>
<!-- here is where you put your Flex Builder 3 Professional license key to remove the watermark -->
				<licenses>
					<flexbuilder3>nnnn-nnnn-nnnn-nnnn-nnnn-nnnn</flexbuilder3>
				</licenses>
<!-- put any other configuration settings you want or need here -->
			</configuration>
		</plugin>
<!-- since the Dashboard app needs a data folder to run, we'll use the resources
				plugin to copy the data folder into the output directory -->
		<plugin>
			<artifactId>maven-resources-plugin</artifactId>
			<executions>
				<execution>
					<phase>package</phase>
					<goals>
						<goal>resources</goal>
					</goals>
					<configuration>
						<outputDirectory>${basedir}/target</outputDirectory>
					</configuration>
				</execution>
			</executions>
		</plugin>
	</plugins>
<!-- here is where we configure which resources we want to copy -->
	<resources>
		<resource>
			<directory>src</directory>
			<filtering>false</filtering>
			<includes>
				<include>data/**</include>
			</includes>
		</resource>
	</resources>
</build>

<!-- where to get the compiler, maven will look at this repository and download required files -->
	<repositories>
		<repository>
			<id>flex-mojos-repository</id>
			<url>http://svn.sonatype.org/flexmojos/repository/</url>
			<releases>
				<enabled>true</enabled>
			</releases>
		</repository>
	</repositories>
<!-- dependency to datavisualization.swc
            the others swcs (framework.swc, playerglobal.swc, ...) are all take by flex-mojos flex super pom Inherit
        -->
	<dependencies>
		<dependency>
			<groupId>com.adobe.flex.sdk</groupId>
			<artifactId>datavisualization</artifactId>
			<version>3.0.0.477</version>
			<type>swc</type>
		</dependency>
		<dependency>
			<groupId>com.adobe.flex.sdk</groupId>
			<artifactId>datavisualization</artifactId>
			<version>3.0.0.477</version>
			<type>resource-bundle</type>
			<classifier>en_US</classifier>
		</dependency>
	</dependencies>
</project>