The data analysis documentation is written to be comprehensive and self-contained, and we will update it based on the comments from the user community.
So how should you begin? This depends on your learning style. If you have a basic understanding of analyzing gamma-ray spectra, know something about the LAT and/or the GBM, and like to learn by example, then you might want to start by installing the Fermitools, and then work through the analysis threads. On the other hand, if you are new to gamma-ray burst spectroscopy, or you would like a more systematic approach, then you might want to start by reading the Cicerone, which provides a detailed description of the analysis environment and its methodology..
If you do not have the software, then start by installing it.
The documentation consists of several sections that will be useful to you at different stages of your mastery of the Fermitools. If you have some questions, you should first check the FSSC Frequently Asked Questions. Your question may already have been answered. Finally, you can request assistance through the FSSC helpdesk.
These pages may be useful for reference.