When writing articles for this blog I often do research on data for economics and finances. I've compiled a number of reference links in my bookmarks. Below are a dozen sites that have useful financial statistics or provide handy calculators.
Social Security Benefits - This is the 'quick calculator' which will give you a very rough estimate of your social security benefits. It just uses your age and current income then tells you the general benefit level. The estimate assumes some things about your previous pay levels so its not accurate to your situation but its good enough if all you want is a 'ball park' figure.
BLS- The BLS or Bureau of Labor Statistics is a wealth of labor related information. They have figures on unemployment, employment, wages, occupations etc.
Occupational Outlook Handbook from BLS - This subsection on the BLS site is all about occupations. Its a great reference to find out what typical earnings are for occupations and what the future outlook for employment is.
Inflation Calculator - BLS is also responsible for tracking the CPI. They offer this handy calculator so you can determine what inflation compares between specific years.
Census Statistical Abstract - The Census site compiles the Statistical Abstract. They have tons of information on various statistics about the U.S.
American Housing Survey. - Another one from the Census. This is all about housing. They have data on housing finances and stats on the structures.
Tax Calculator and Tax brackets- These two pages from MoneyChimp are nice quick references to income tax information. The calculator will give you a quick figure on the tax liability for standard deduction and you can also manually put in itemized deduction amounts and multiple exemptions.
California Tax Calculator - If you happen to live in the state of California then you can get a quick estimate of your income tax bill with this page.
IRS Tax Statistics - This is a subpage on the IRS site with their stat data. They have a bunch of Excel sheets with data on tax collections and details of tax filings going back a few years.
Budget of the USA - You can find out specifics on federal government spending.
Student Loan Calculator. - Finaid.org gives us this handy calculator to determine what your student loan monthly payments will be.