Help on my employment tax form...?

Hello, I need help filling out my tax form. I am in the state of TX...my status is common law marriage and I filled for a joint tax return with my partner and claimed my daughter and my spouse...or common law spouse...and received a satisfying refund...for 2008...I am the only one working making 25,000 per year supporting (3) myself,my spouse, and my child....do I claim for exemption or not.....or if anyone can... send me a sample of how the W-4 employment form should look like...thank you....