I have a Canon PSSX10is and need to photograph a lot of letters typewritten

My first trials showed some letter not 100% parallel-perfect ...

What is the best method to avoid lens distortion and obtain the best of the lens?
I want perfect definition of letters, corrections, typos, etc.

How to set the ideal distance, mode: automatic? iso, etc, diafragm, zoom, etc?)

The seller told me that this was a perfect camera for this job.

Thanks.