Why do I owe taxes when they have been taken out of every form of income?

[unclewutang]

Is it because I claimed myself and my 3 children as dependents on my w-2's

[Hal_Al]

Yes.  Or, in general, your withholding wasn't enough.   Withholding is just an estimate of the final tax due.  It's unrealistic to expect to be exact.  "Everybody" either owes or gets something back.