Resampling in Photoshop

[hacimd]

I'm looking for opinions on using re-sample option when upscaling for print in Photoshop CS-6.  Is there a standard rule when upscaling or is this something that is not always necessary?  Any info would be greatly appreciated.

 

[digitaldog]

Resampling means adding or removing pixels. When adding (sizing up) for images use BiCubic Smoother. For sizing down, BiCubic Sharper. In CS6, the new Auto setting in Preferences will automatically select this when it ‘see’s you are sizing up or down. In the old days, you had to manually select this.

In terms of best practices for sizing up, this should help:
http://www.digitalphotopro.com/technique/software-technique/the-art-of-the-up-res.html?start=1