I've been checked out over the course of more than 20 years in multiple locations in states from Florida to Washington. Here's my experience.
First and foremost, I always get in touch well in advance to find out the FBOs procedures. FBOs are independent businesses and their procedures can be very different. Renting a 172 in one location could mean a simple 45-minute flight with a CFI; in another it could mean a more extensive flight and a knowledge test that takes hours. In areas, like Florida, which do a lot of international student training, you might even be asked to supply proof of citizenship.
I also try to do as much as I can in advance. If the FBO has an extensive application process, I find out if it is downloadable so I can do it by email. If they need some some of documentation I ask how much of it I can supply scanned or in some other electronic format. (I generally prefer FBOs that do business online - that means do business, not just have an email address they never respond to.)
Speaking of electronic formats, I don't particularly like to travel with my paper logbook, so that's another thing I ask. All FBOs will want to verify currency and experience, but they can be different in what they will accept. I've rented from places that insist on my paper log (although it no longer shows my currency except for my flight review) but, more and more I have seen electronic logbooks, backed up by a scan of a current flight review, accepted.
For the checkout itself, again it varies from FBO to FBO. You can expect, at a minimum, to demonstrate a standard subset of Private PTS maneuvers - slow flight, stalls, steep turns, as well as engine out emergency procedures and, of course, takeoffs and landings. FBOs in densely populated areas will also generally engage in an area familiarization - which is something I would never complain about!
BTW, another option: As much as I want to fly around, vacation time tends to be family time and I'm really not going to fly that much. Many times there is simply no flight after the checkout. So, why not skip the checkout and use the CFI as a guide for an area familiarization flight when you fly the airplane and see the sights? Unless I am checking out for the purpose of going somewhere else altogether, that's an option I have chosen regularly.