Imagine an employee whose never had a job and has a ton of questions about the W-4, I-9, etc....how do you go about managing this?
Most companies have new hire packages which accomplish this. Make sure you get direct deposit at the same time. You cannot say that it is mandatory but you can imply it.
I had one page instruction/explanation sheets with each form. W-4 is easy. The form is legally optional but Single-Zero withholding occurs if you fail to fill it out. I-9 is not optional. No form, no job. Most companies have a new hire orientation during which the forms get filled out. I have worked for companies large enough that we brought in new hires on Mondays and payroll sent someone over for around 1/2 hour to answer questions (and sell direct deposit).