I agree with the PP - renting involves a lot of trust from the rentee, if you are at all uncomfortable with the degree of communication and information you are getting from the renter, you are not obligated to rent from them.
There is a great sticky about renting points at the top of the rent/trade thread. I've rented points one time and in my experience, a good transaction will follow these steps:
1. email contact - mutual exchange of information
2. phone contact - mutual exchange of information
3. renter sends confirmation letter and two copies of the contract in the mail to rentee, rentee has X number of days to return the signed contract and a deposit to the renter.
At this point, you are obligated to continue the transaction.
If, at any time, a red flag seems to go off - the renter seems to have given sketchy contact information, is asking for payment up front, etc - then look for a different renter.