Hi Geo,
I've a bit of experience with AEM Guides and I agree with you on that you can follow the documentation to easily use and support AEM Guides project. I would like to point that familiarity with DITA is crucial to understand how different tools are working to generate the output either Site or PDF or other format. Secondly, I would suggest digging into the Publishing process which internally uses the Sling jobs to generate the output.
Thanks,
Lokesh