Here you can view a guide to finding your NAICS codes. NAICS is the uniform classification system for all contracting activity in the U.S., Canada, and Mexico and is needed to register in SAM for federal contracting – http://www.census.gov/eos/www/naics/
Virginia PTAC blog entry on the topic (recommended reading!): https://virginiaptac.org/ode-to-the-naics-code/
Resource Link: http://www.census.gov/eos/www/naics/
You can register for SAM, the System for Acquisition Management here. SAM is the centralized process of registration for vendors that want to do business with the federal government. It is also the primary repository of the federal government for all of your company’s required representations and certifications
In the future, multiple federal sites are being merged into one, you can use and view the site as it exists currently at beta.sam.gov and the site will eventually replace sam.gov when the transition is complete.
Resource Link: https://www.sam.gov/SAM/