I currently attend a state university. I have been receiving the Post-9/11 GI Bill education benefits, and was wondering if they are taxable.

No, any veterans benefit paid under any law administered by the Department of Veterans Affairs should not be reported as income to the Internal Revenue Service. Per IRS Publication 970, "Payments you receive for education, training, or subsistence under any law administered by the Department of Veterans Affairs (VA) are tax free. Do not include these payments as income on your federal tax return."