Which IRS publication is primarily focused on providing tax information for small businesses?

IRS Publication 334, titled "Tax Guide for Small Business," is specifically designed to provide essential tax information and guidance to small business owners. It covers important topics such as business income, expenses, and various deductions and credits available to small businesses. This publication is invaluable for entrepreneurs and small business owners as it helps them navigate tax obligations and understand how to report their income accurately.

The other publications listed serve different purposes: Publication 550 deals with investment income and expenses, Publication 543 provides information on tax-exempt organizations, and Publication 463 focuses on travel, gift, and car expenses. Thus, while each publication is beneficial in its context, Publication 334 is the focused resource for small businesses seeking tax information.