You can find the full list of ATGs on this page of the IRS website.
The industries covered range from daycare providers to attorneys to the wine industry to the aerospace industry. These guides make for fascinating reading for tax nerds. The key thing to remember when reading an ATG is that this is the IRS’s viewpoint on how tax law applies. If a tax pro is trying to construct a defense for their client, or figure out whether a deduction can be taken, etc., one also needs to consult court cases and review the regulations yourself. But the ATGs are a good, solid resource for typical situations that arise.
For more tax terms with simplified definitions, check out the Glossary page.