Latex paint can often be dried out and thrown away with your normal trash, but oil paint is hazardous and must be taken to a waste collection site.
How to Dispose of Paint the Right Way
Krud Kutter 3.5 oz. Waste Paint Hardener PH3512 - The Home Depot
Don't Dump Paint
Paint Disposal Guide — the Green Project
Latex Paint Disposal - Hendricks County Recycling District
Solid Waste - Paint Disposal Solid Waste Department - Rutherford
How to Dispose of Empty Paint Cans: Latex & Oil-Based Paint
How Do I Dispose of Paint?
How to Dispose of Paint Properly and Safely
Dealing with Oil-Based Paints and Stains – Storage and Disposal - NEDT
How to Dispose of Paint and Paint Cans