This tutorial gives a guided tour through the programs included in the “samples” subfolder found in the installation folder. It also contains material introducing the command line interface along with hints and suggestions for using tioga effectively.
By the way, the tutorial assumes you want to use Ruby directly to write the programs that describe the figures and plots. If instead of that you'd prefer a command-line interface along the lines of gnuplot, then be sure to read all about Ctioga. Basically, Ctioga writes the ruby program for you, making it easy to do easy plots while still having the ability to do complex ones by adding options to the command line.