Some time, you make mistakes, and want to roll back to see what last version working fine, and want to see the difference, then....Versioncontrol: none, did not have a need for this until now.
When you say, I write a readme file, etc. Its always best to pack all of them into a installer, generally most installer does nothing more than copying the files to a folder. They provide added benefits like compression, and are a 10 minutes job for a simple one.Most of my programs are able to run "out of the box"
Try using doxygen, its generally very easy and makes your documentation in a standard format, and you can generate your doc book in any format with that. If using Visual Studio.NET must check kings tools from CodeProject.For public Apps, i also write a Read me, or even a Handbook.
Also when you are making UML, try it to also generate code from it.