There is a wealth of material available on the web.  Listed below are some of the links that I have found useful.

Taxlibrary
Offers the complete online library for tax professionals. This Internet tax research-based  product features information from CCH, Harcourt Brace, and Tax Analysts.

AICPA
The American Institute of Certified Public Accountants site, with a wide range of information for both members and nonmembers.

Federal Court Locator
Access federal judiciary decision here courtesy of the Center for Information Law and Policy.

QuickBooks
Check out this product from Intuit.

Department of Treasury
The homepage lists everything from the Treasury's mission and goals to organizational information.

FASB
The Financial Accounting Standards Board has exposure drafts, news releases, publications and other information emanating from the Board and its task forces.

FedWorld Information Network
If you're looking for information published by a federal government agency, this is the place to find it. Included here are the Fed World Libraries, the Government Information Locator Service, the IRS, U.S. Treasury, the FAA, FERC and more.

Federation of Tax Administrators
A good place to start for state and local tax information. Some helpful tax documents and good
tax-related links are here.

General Accounting Office
This site contains GAO reports and testimonies, comptroller general decision and opinions, among others.

GASB
The Governmental Accounting Standards Board has all the various governmental financial statements.

Internal Revenue News
You can download weekly Internal Revenue news items here.

IRS Home Page
This homepage, featuring a colorful e-zine called The Digital Daily, is where you can access news, forms, tax calendars, statistics and more.

Practitioners Publishing Co.
Free, currently updated excerpts from many of this vendor's high quality accounting publications.

National Association of Computerized Tax Processors
The NACTP represents tax processing software and hardware developers, electronic filing processors, tax form pulishers, and tax processing service bureaus.

Research Institute of America
The Hot Weekly News section contains highlights from Washington, D.C., federal taxes, state and local taxes, pension and benefits, estate planning and international spotlight. RIA product information from CLR is also here.

Nelco
Nelco is a national supplier of forms, supplies and electronic filing software for the industry.

PriceWaterhouse Coopers Tax News Network
A source of daily tax news which draws on diverse respected sources such as BNA, Tax Analysts, Warren Gorham & Lamont, and Coopers & Lybrand. 30 free trial.

CCH
A wealth of information for accounting, legal, human resources, securities, insurance, health care and small business professionals.

Tax Code Online
Cornell University maintains this Web page that is generated from the most recent version of the Government Printing Office CD-ROM.

SEC
The Securities and Exchange Commission site with its Edgar database of corporate information.

Professional Digital Services
A company dedicated to more than just designing and building first class web sites.  PDS knows how to promote your web site and is responsive to customer service and needs.

State Statutes
Courtesy of Cornell Law School, you can access a lot of statutory source documents here.

Mortgage & credit information
Extensive information about latest mortgage rates, where to find them, mortgage calculator, financial tips.

Check for your refund
IRS site to check status of your tax refund.

Social Security on line
Latest information from U.S. Government about Social Security