Invoice Ninja - Invoice Ninja is a free, open-source solution for invoicing and billing customers.
Freelancer Stack - Curated directory of tools used by 10,000+ freelancers
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Hourly - Find out how much you should charge per hour
FreshBooks - The ideal accounting software for small business owners.
The Standard Freelance Contract - The first common standard service agreement