USCIS provides guidance for employers in the form of a 69-page document, Handbook for Employers, Guidance for Completing Form I-9, (Employment Eligibility Verification Form). As a reminder, this 69-page handbook provides instructions, tools and tips as well as frequently asked questions to complete a two-page form. All employers are required to be using the newly updated I-9 form as of January 22, 2017.
The USCIS has now come out with the newly updated M-274 that can be downloaded here.