what version of Linux is best and why?

Any of the mainstream distros. Ubuntu, Fedora, and a few other well known distros. The more popular ones are popular for a reason. Stay away from the latest releases even if they claim they are "stable". If you go with the newest release, you may find yourself lost trying to work around a bug or other problem that no one caught.

In the small and light category, Puppy is possibly the easiest small distro to use. At only 100Mb, it will run in memory on a lot of older systems. A bit harder to use is DSL though it comes in an even smaller package.

If I say much more, it will just be an opinion. I personally use Fedora. On the other hand, I also have Linux installs that go back to some really old kernels that had to be configured manually.

Shadow Wolf

The major distro are all easy to use but you have to read and follow the instructions on the website. Linux does things differently than windows and the only way to know how to get thing done in linux is to have someone guide you step by step or read the documentation and manual.

Good luck