Internships in Congressional Offices: Frequently Asked Questions [Updated April 27, 2022] [open pdf - 1MB]
From the Summary: "This report addresses frequently asked questions (FAQs) about congressional interns and internships. It is intended to provide information to congressional offices about the role of interns and to provide a summary of some of the policies and guidance provided by the House and the Senate related to internships. It addresses the House and Senate rules that apply to congressional internships, factors that may affect an office's selection process and an individual's eligibility to serve in an internship, and some of the congressional resources and training opportunities available for interns."
CRS Report for Congress, R44491
Congressional Research Service: https://crsreports.congress.gov/