How Stuff Works provides instructions on how to use laser levels and explains the differences between types of laser levels. Laser level manufacturers such as Skil also commonly post guides describing how to use their products and explain which type of level works for each project.
DoItYourself.com and other similar do-it-yourself websites typically post instructions describing how to use laser levels. YouTube also has numerous videos showing how to use a laser level properly. Laser levels come with small instruction manuals showing owners how to properly use the tools, and manufacturers sometimes post their instruction manuals online for replacement needs.