I am studying for the ATPL exams. As an FAA-authorized CFI/MEI I am a nerd and stickler for understanding my material
I miss the FAR/AIM structure

Where can I find the regulation concerning cruising altitudes, for example? I have the JAR OPS 1 (amd 13) document, but can't find it in there.
PS: I know the cruising altitudes, but am wanting to learn the JAR regulation structure and where I can find the various regs.
Thanks for the help