Basics
Background you may or may not need: SSN, ITIN and EIN, a US mailing address, and when a US company is worth it. Many guides need none of these.
3 guides
SSN vs ITIN vs EIN: Which US Number Do You Need? What the SSN, ITIN and EIN are, who can get each one as a non-resident, how the W-7 ITIN process works, and what each number unlocks. 
Getting a US Address as a Non-Resident Virtual mailbox, a friend's address or a registered agent? How USPS Form 1583 works, and which banks and fintechs reject mailbox addresses. 
US LLC for Non-Residents When a US LLC is worth it, Wyoming vs Delaware costs (including Delaware's $400 tax), formation services, getting an EIN without an SSN, and Form 5472 duties.