Keeping good records after you file your 
taxes is a good idea, as they will help you with documentation and 
substantiation if the IRS selects your return for an audit. Here are 
five tips from the IRS about keeping good records.
1. Normally, tax records should be kept for three years.
2. Some documents — such as records 
relating to a home purchase or sale, stock transactions, IRA and 
business or rental property — should be kept longer.
3. n most cases, the IRS does not 
require you to keep records in any special manner. Generally speaking, 
however, you should keep any and all documents that may have an impact 
on your federal tax return.
4. Records you should keep include 
bills, credit card and other receipts, invoices, mileage logs, canceled,
 imaged or substitute checks, proofs of payment, and any other records 
to support deductions or credits you claim on your return.
5. or more information on what kinds of 
records to keep, see IRS Publication 552, Recordkeeping for Individuals,
 which is available on the IRS website at www.irs.gov or by calling 800-TAX-FORM (800-829-3676).
Link:
Publication 552, Recordkeeping for Individuals (PDF 61K)