Can somebody tell me what the interview and hiring process is like at Home Depot?

Take the test online. (read the questions twice.) Ask for the wage that you want. (Raises are very low.)

Wear a tie,(or nice business-like outfit.) look them in the eye, stick your hand out and introduce yourself and be cheerful!

Tell them that you love HD and that you will do a great job.

The interview will unfold naturally.

Ditto on FormerTool's comments, except I wouldn't wear a jacket unless I were interviewing for a manager position.
For the last couple of years HD has been using nine standard questions. They will ask all nine. Some of the nine are about as follows, in no particular order:
a) What qualifications do you have for this position?
b)Tell me about a time you took care of a customer, or an upset customer, or something like that. I forget exactly.
c) Why do you want to work in retail?
d) Tell me about something good you did for a coworker or supervisor.
e) You are helping a customer. Another customer asks for you assistance. There is no other associate around, and no phone to call help. How would you handle this situation?
f)Tell me about a time you missed a deadline.
g)What have you learned new in the last year?
...Plus another I can't recall - something about dealing with fast paced or stressful situations or something.
Some other points in doing well in an interview:
Make sure you like people and understand that somebody who has a broken toilet and is making their third trip to HD can be pretty cranky.
Be sure you can roll with the stress of many demands from customers and managers.
Try to show some learning agility. You will need to learn a lot about departments next to the one you work in, and enough to answer the basic questions in most other departments.