Apart from downloading the mevenide binaries, you need to setup the MAVEN_HOME and JAVA_HOME environment variables. You can do it in the netbeans install dir's etc/netbeans.conf file. For details and alternate ways, see MEVENIDE-88 bug report.
Courtesy of Travis Risner.
When you get red underlines for classes and methods from one of your dependencies, please check if you define it's type element. Make it either jar or ejb, depending on the type of the dependency.
Put the jar with javadocs into your local repository (in the group's folder create a "javadoc.jars" subfolder), give it the same name as the jar and the "javadoc.jar" extension (instead of default "jar") and the IDE will find it. When the javadoc is on remote repository, just declare additional dependency of type javadoc. In the latest versions of maven-javadoc-plugin, the javadoc's artifact type was changed from "javadoc" to "javadoc.jar", so the javadoc file should be put into the "javadoc.jars" directory and have the extension "javadoc.jar". If you have the project opened, the javadoc:install goal will create the javadoc and put it in the local repository for you.
Similarly as the javadocs, the jar with artifacts sources belongs to the local repository under the src.jar category. So for example for log4j-2.8.3.jar dependency, the sources belong to ${maven.repo.local}/log4j/src.jar/log4j-2.8.3.src.jar
Use the multiproject plugin's properties
maven.multiproject.basedir
and
maven.multiproject.includes
to denote your subprojects. When opening such project, the subprojects can be opened as well. Refactoring and other cross project features work then on all the projects.