Don't do it. This is a SCAM!
Instead of trying to do it yourself, I suggest you work with a licensed Real Estate Agent who specializes in Leasing.
They can help you find a place, complete the application, and make sure you get the place all at no cost.
Here's how the process usually works:
First complete the standard Rental App, but leave the property address blank. I have all my clients do this so their paperwork is ready when they find a place to live. In addition, I need a copy of your driver's license, and copies of your last 2 paycheck stubs to verify your employment (so the landlord can see how you are going to pay for the place)
Then I will send you all the properties that meet your criteria (size, price, location), and we can schedule a time to go look at them together.
When you find one you want to live in - we submit your application (already completed) and a small application fee to process the paperwork - usually less than $50.
When you have been accepted, we then submit the deposit to hold the place.
Let me know if you have any other questions,