Within these three categories are a variety of funding sources and program types. Federal Grants, Funding & Benefit Programs. To sort through the federal and state grants. 

How to start a 501(c)(3) tax-exempt nonprofit organization.

Tax exemption under Internal Revenue Code section 501(c)(3) provides a number of benefits:

Exemption from Federal income tax;

Tax-deductible contributions;

Possible exemption from state income, sales, and employment taxes;

Reduced postal rates;

Exemption from Federal unemployment tax; and Tax-exempt financing.

How to write a grant proposal: a step-by-step guide - Grant-proposal

Other funding sources and sustainability