If you find that you're still lost, have no fear. You can find additional help and research guides at other Law Library sites.
A great place to check out is the Furman Smith Law Library at Mercer University School of Law guide authored by Jeremy Simpson - Federal Income Taxation - Beginner's Research Guide: Introduction. This guide will give you a great foundation along with helpful information on where and how to find tax forms and other resources.
The New York University Law Library offers a very robust tax research guide with the Federal Tax Research: Outline & Guide Information. Once you have an idea of what you need to be looking for, this research guide will point you to several comprehensive sources. Some of the listed resources require NYU student subscription access, but there are many freely available resources to check out.
The University of Florida Levin College of Law also offers a Tax Law Research Guide, especially if you are looking for more substantive tax issues that are not covered in this guide.
https://www.taxpayeradvocate.irs.gov/