Since the Administrative Procedure Act (c. 324, 80 Stat. 237 (1946)) was passed, most federal regulations must be created by a process called "notice and comment." This means that when a regulation is being created, public notice must be given. This notice must include the proposed text of the regulation. The comment portion requires agencies to allow the public to participate in the creation of regulations by giving them the ability to express their opinion about the regulation to the agency.
Detailed descriptions of regulations and the rule making process are available from the Office of Information and Regulatory Affairs in their FAQs, including The Reg Map, and from the Office of the Federal Register in: A Guide to the Rulemaking Process.
The Reg Map divides the process of creating a regulation into 9 steps. The last tabs of this research guide follows the organization of The Reg Map. After each step, a brief description of the step is provided , followed by a list of the sources you can use to find out if the step has happened or is happening, along with information about documents that have or will be created during that particular step. The last tab lists all the information created during each step of the process.
Glossary at Regulations.gov: definitions of rulemaking terminology.
Other useful numbers: