Rules, proposed rules, and notices of Federal agencies and organizations, as well as executive orders and other presidential documents are published daily in the Federal Register. Permanent rules published in the Federal Register are then codified by subject in the annual Code of Federal Regulations (CFR).
When searching for federal laws enacted by Congress, you can search the U.S. Statutes at Large by date, or the U.S. Code by subject.
Most States now make regulation or administrative law codes available on the website, either in total or on the individual department or agency website. Go to Google and type in the terms "administrative code" and "name of state."