The easiest solution if you are just starting a new project is:
- Create a new project in NetBeans and in the "New Project" wizard under "Categories:" select "Maven" and under "Projects:" select "Java Application"
- Hit "Next >" in the wizard
- On the next page keep all defaults and hit "Finish"
- The project is created
- Switch from "Projects" view to the "Files" view in the top-left
- Open the pom.xml file
- Go to https://lwjgl.org/download
, select "Nightly" and under "Mode" select "Maven"
- below the now visible "Snippets" section to the right click "COPY TO CLIPBOARD"
- Get back to NetBeans with the opened pom.xml file, position your keyboard caret right before the closing </project> tag and paste from clipboard (Ctrl+V)
- Now you'll see that you have two <properties> elements. Merge them to one by removing duplicate entries.
- Now to ensure that NetBeans downloads the Maven dependencies of LWJGL 3, get back into the "Projects" view, right-click on the "Libraries" node/tree-item and select "Download Declared Dependencies". You probably have to wait one or two minutes for NetBeans to download all required Maven dependencies. That is indicated by the progress bar on the bottom right.
- You're done.
Disclaimer: I never worked with NetBeans, but the above quick process worked for me in NetBeans 8.1