Birth Certificates, death certificates and marriage certificates, custody agreements, deeds, divorce papers, etc., should be permanently maintained.

Documents related to non-deductible contributions to your IRA should also be permanently maintained.

Tax Returns and related support (receipts, etc.) - should be kept for the current year plus the prior three.  Documentation would include W-2's, 1099's, 1098's, contribution receipts, etc.

Note: For contributions of $250 or more, you must have a receipt prior to filing your tax return.