How to use W-2's on tax returns as a graduate research assistant

Hello,
currently I am a graduate student (full time). I recieve a monthly stipend as well as my tuition paid for. I have a 1098-T and a W2 form. A lot of taxes are not taken out of my monthly stipend so i'm afraid that we will owe money. I only work 20 hours a week and only 9 months out of the year. My husband is the main provider for myself and our two kids.