Getting it ready was a bit like putting together Ikea furniture (if any of you have had to put together Ikea's Expedit bookcase, you know EXACTLY what I'm talking about): it looked deceptively easy. The short story is that you inflate the bed a little bit, you add the exact amount of lukewarm water, and then you do a bit of the chicken-dance on it to create the "bed core" and drive the air out toward the valve. Then, if all goes well, you let the bed set until it's cool to the touch.
After a week of having it, and some false starts with getting the bed right, my dog is now glued to this mat, indoors and outdoors. One thing to note: Based on how this mat is built, I wouldn't recommend this for dogs who like to chew things.