The most used sections of the manual are in the References portion 4.3.
4.3.2 Creating References - in text citation options
4.3.3 ACS Style Quick Guide - basic info on the bibliography and reference list
4.3.5 Reference Formatting & Examples by Source Types - more in-depth information on bibliographic and reference list
Styles such as ACS and AMA require an abbreviated journal title in the reference list. This can be tricky to do if the journal did not publish the abbreviation on the article itself. But there is an easy way to construct one. Both styles use the same formatting, and they stay standard every time that word is used in a title. Once you know how a particular word is abbreviated, you can use it over and over.
To look up how a word is abbreviated, here is a simple hack: