General
Accounting Terms - dictionary.
Chart of accounts - described
Business records retention - Determine how long you need to keep records
Business structure - comparisons (sole proprietorship v. S corp v. LLC, etc.).
Social Security Statement - request a personal statement online.

IRS Current Forms and Publications
W-2 and W-3 Instructions
W-4

I-9 - pdf of Employment Eligibility Verification.
W-9 Request for Taxpayer ID# and Certification
1099 A and C Instructions 
Standard Mileage Rates  - IR-2006-168
Tax withholding and estimated taxes - Publication 505.
Independent contractor vs. employee?
Tax due dates 

Nonprofit Organizations (NPOs)
Nonprofit organization (NPO) accounting terms - a glossary
Accounting regulations
Accounting standards 
California Association of Nonprofits 
Form 990  

Calculators and Conversion Tables
Financial Calculators- Any financial calculator you need.

State
California Department of Industrial Relations
California Board of Equalization
California Franchise Tax Board
California Employment Development Department (EDD)
California State Tax Rate