These are useful links to small business and self-employed IRS resources on their website:
A-Z Business Topics
Search the IRS website by business type, subject or topic.
Calendar
View due dates each month using the online IRS tax calendar.
Coronavirus Tax Relief
Employment Tax
Employer ID Numbers
Forms and Publications
Gig Economy Tax Center
Payroll Professionals Tax Center
Retirement Plans
Self-Employed Tax Center
Self-Employment Tax
Tax Centers by Industry / Profession
Agriculture
Real Estate
Trucking
Recordkeeping
Tips
Information about tips.