Publication 526, Charitable Contributions
This publication explains how to claim a deduction for charitable contributions. It discusses organizations qualified to receive them, the types of contributions you can deduct, how much you can deduct, what records to keep, and how to report them.
Publication 538, Accounting Periods and Methods
This publication explains some of the rules for accounting periods and accounting methods. It is not intended as a guide to general business and tax accounting rules.
Publication 542, Corporations
This publication discusses the general tax laws that apply to ordinary domestic corporations.
Publication 947, Practice Before the IRS and Power of Attorney
This publication discusses who can represent a taxpayer before the IRS and what forms or documents are used to authorize a representative.