re: Best way to allow withholding to sit for tax season?

Let's say you paid $10k in federal taxes last year, on your teaching income. As long as you pay at least $10k this year, either through regular withholdings or estimated payments, you should not get hit with an underpayment penalty when you file and write a check in April. People really understimate the power of this rule. Disclaimer:I am not a tax CPA so I'll defer to the regulars, but I have dealt with this personally.