Owner, Maintenance and tenant all have a slightly different idea of what a property should look like when it is available for rent. You can't please everyone, but if you try to please the majority you will have success as an owner or property manager.
There are tons of TV shows, and books on the subject. However here is a quick example of what I think rent ready means.
Quick example... When we stop at your favorite hotel for the night what type of condition do you expect the property to be in? Why is this your favorite hotel? The answer is most likely that its convenient to everything, it is priced right, and it is in great condition. Is everything brand new? No, it is just very well maintained and replaced if it needs to be.
Now when you get to the hotel do you expect the key to work easily, are the carpets clean and odor free, are the walls freshly painted, with no scuff marks. Do all the lights work? Does the heating or A/C work as expected? Is the bathroom well maintained and clean. If you have an issue does the maintenance staff resolve ASAP?