Go to the main LJM Page for an introduction, and proceed to the LJM User's Guide for more details.
Perhaps most importantly you need to understand the ' dataflow' concept, which is one of the biggest differences between LabVIEW and a text language. If you are new to LabVIEW, you need to know the basics such as loops, case structures, arrays, clusters, data types, indicators and controls. Experienced LabVIEW programmer? Proceed to next step.