Found a great resource on Theoretical Mechanics (free)

[smodak]

Classical mechanics: a minimal standard course by Sergei Winitzki. It is not probably going to help you if you already did not know the subject but is a great refresher nonetheless. He also includes a differential equations refresher that I found invaluable.

Looks like he has a ton of other resources available on his site: https://sites.google.com/site/winitzki/ as well including advanced GR and quantum gravity.

 

[SredniVashtar]

Here's a detailed review of this book:

To be written.

(Sorry, I couldn't resist).
BTW, it appears it's (half) written in Mathematica.