Dumbduckie,
Perhaps this will help you out.
Complete guide to Western Union
As you can see, the guide was created nearly 2 1/2 years ago. Western Union has made a few changes, but I find it to be very basic. I had used Western Union for business in the past.
Basically, you should be able to provide an ID when sending/receiving money. I believe you have to show it on sending, but I'm not 100%. However, when receiving money, there are certain forms that may be required to show/prove you are who you are, and you live at the address provided on the form.
When sending money, you'll need to provide all relevant information to the customer (full name, address, city/state/province, etc). This is information that they will have to provide/verify when receiving the money. There are fees involved, but it will insure safe transfer of funds (if in a large sum).
You will be given an MCTN that will need to be provided to a Western Union Agent for the one receiving the money. Other than verifying informing, keeping the MCTN safe, and making certain the funds are secure (perhaps use a Middleman), the use of Western Union is essentially a simple process.
My response may seem a little elaborate or over the board, so I apologize if there is any confusion what-so-ever. If this is the case, or you cannot find the information you're looking for in the guide, by all means please PM me.
Hope this helps and best of luck.