This handout goes along with the IRS's student site to explain income taxes. All directions are listed in the handout, but it is a great resource to have students learn about the different forms like the W2, W4, 1040EZ, etc. You can add more simulations for higher level classes, etc, as this is an editable file.
The resource is great, although I wish it had an option of submitting the student work online to the teacher. Since they do not- this is why I have created this assignment to go along with it. Any time a student clicks on an answer or types one in - that's what the numbers are for. They write it down. It keeps them accountable and from speeding through the assignment.