The normal starting point is then to use the GREG graphic program, which will give you a first experience with the SIC command monitor. It is recommended to read first the SIC and GREG Cookbooks (15 and 5 pages respectively).
To get really started with image processing, read the GILDAS chapters 2 and 3 (Running Tasks, and Displaying Images) trying to run some of the image processing tasks (8 pages). However, since GILDAS is an image processing system, some practice with the GREG2 GREG language will be soon necessary. This practice can be done using the GRAPHIC program, but reading the GREG Manual will help (12 more pages).
Reference to more specific sections of the SIC and GREG documentations become only necessary for advanced users, and obviously for programmers. While the user become more and more familiar with GILDAS he (or she) will find that constant reference to the documentations is hardly ever necessary. The internal HELP is usually sufficient.