Below are links to assist you.

Internal Revenue Service
The IRS is the US government agency responsible for tax collection and tax law enforcement. Contains downloadable forms, instructions and more.
https://www.irs.gov/

California Franchise Tax Board
The department that collects state personal income taxes and bank and corporation taxes for the State of California. Access to forms and tax information.
https://www.ftb.ca.gov

Additional Resources:

Small Business and Self Employed Tax Center
https://www.irs.gov/businesses/small-business-and-self-employed-tax-center

Small Business Forms Publications
https://www.irs.gov/businesses/small-businesses-self-employed/small-business-forms-and-publications

Tax Calendar for Small Business and Individuals
https://www.irs.gov/businesses/small-businesses-self-employed/irs-tax-calendar-for-businesses-and-self-employed

Self Employed Individuals Tax Center
https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center