Taxing

IRS – The IRS site for official taxing administration
Social Security Administration – The SSA site for Social Security matters


Financial 

Career Direct – Find the career that suits you best
Crown Financial Ministries – Larry Burkett's page of sound financial advice based on biblical principles
InvestorGuide – An excellent guide to investing on the Web
BankRate – Financial and investment news and advice

Tax Professionals

Drake Software – All-inclusive tax preparation software for the tax professional
Drake Electronic Training Center – Earn CPE credits and learn basic and intermediate tax law
Taxing Subjects – News, articles, and references for the tax professional 
NACTP – The National Association of Computerized Tax Processors
NAEA – National Association of Enrolled Agents
NATP – The National Association of Tax Professionals 
AICPA – American Institute of Certified Public Accounts