Every job you have will provide you with a W-2 form, whether or not you are full-time or part-time. If you are a contractor then you might get a 1099 form. You could be part-time and still have over 40 hours per week periodically. Just make sure that you have a W-2 form for each job. The W-4 form lists how many deductions you want when taxes are withheld each paycheck. Personally, I prefer to go with Single 0 unless there is a better reason to have less taken out each paycheck.
