LingTree is a relatively simple program.  It comes with two resources, both of which are accessed via the Help menu item.

The user documentation is at Help menu item / User Documentation.  Please read this (relatively short) document to learn about what LingTree can do. It is also available online at User Documentation.

The second resource is a Quick Reference Guide.  This is a summary of what to key in order to get a certain effect in the tree diagram. Use Help menu item / Quick Reference Guide to see it.

Both of these resources will stay showing while you work on a tree diagram (the user documentation is a PDF file).  This is an attempt to make them handy for quickly seeing what you need.

Some sample tree files are also available. Click LingTree Samples Zip file to obtain a zip file containing them.

You can also see the LingTree Helper web site for another way to key tree diagrams that some users find more intuitive.