Which one of these cameras is the easiest to use?

Canon EOS Rebel T3i and Nikon D3200
Easiest to use and most user friendly for a novice photographer

Both are entry level dslr built for novice, if you read the notice you won't have any problem.

The Nikon D3200 has a special "guide mode" that some new users of dSLR's find helpful

In general All dSLR's work the same, so if you know how to use a light meter, you should find no difference when it comes to ease of use.

Nikon's D3xxx series has a guide mode that is helpful for some new users. It is more or less a tutorial built into the camera. My son (has a D3000) found it very helpful when he learned the basics.

Nothing in it.