I withdrew my 401k in 2010, now I have to do my taxes , since my wife runs a childcare at home , How can I get refund showing expenses?

If your wife is running a business you should be filing a schedule C to document her income and expenses. I can't tell you whether you'll get a refund or not - don't forget that if you are under age 59-1/2 you have to pay a 10% early withdrawal penalty on the 401(k) withdrawal in addition to regular income taxes.

AND that 10% Early Withdrawal Penalty CANNOT be reduced by credits or deductions, since it is a punitive tax designed to discourage early withdrawals.