How you meet is up to her but most of the time she will just call you for the room number and come on up.  If the hotel has a secure elevator or a security presence in the lobby you will probably want to either meet her in the hotel lounge or outside.  You really don't want to do it in the lobby.

When she will want the money is also something that should either be on her website or ad.  If she comes to your room have the money in a plain white envelope in plain view when she arrives.  Don't hand it to her and don't make her ask for it.  It's doubtful that she will want to be seen receiving an envelope from you in a public place but if you are not sure simply bring it with you but do not hand it to her unless she asks for it.

Stan, try not to overthink it...my 2nd time was an outcall.  I booked a 3 hour session so we could have some time to have a drink in the lobby before heading up.  But in general, you give her your room number and she would meet you in the room.  Leave the donation in a plain envelope in the bathroom so when she goes in to freshen up and change she'll see it.  If you happen to meet in the lobby, valet, or for a drink you can leave the envelope in the room or give it to her in a giftbag (I think that's cheesy though)...best bet, just discretely ask her when you are setting up the appointment.

She will "have it down" when it comes to intro, if in public I am overly discrete.  Nothing more than a peck on the cheek so it appears you either may be two people meeting for a first date.  Remember, she hsa most likely been through this more times in the past month than you ever have and she should be able to deal with almost every reasonable situation.

Good luck!

IN or OUT calls work the same way.  Person arrives & calls for room number.  Gift is left in a visible place either on a table or in the bathroom.  
Rarely will a meeting begin in the lounge, but if it does, the donation should still be done in private.  
The only exception is where a key card is required for the elevator.  

The protocal, is the room resident opens the door.  The other party enters the room.  The door closes & latches.  You exchange a hug & a kiss.  You throw the night latch on the door.  Move into the room...   she will note the donation envolupe, might pick it up or not until later.  You do not referance the envolupe or even look at it.  

Have Fun.
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