Even if you work 100% traditionally, in the digital age we live in you’ll probably be required to scan or photograph your final artwork before sending it to a client. This can result in a digital file that may need some Photoshop tweaks to get it ready for print.
Here are 4 tutorials to help improve your skills from PSDtuts, the amazing online resource for all things Photoshop:
Quick Tip: Color Correction in Photoshop with the Curves Adjustment Tool
10 Steps to Improving Your Photoshop Skills
A Comprehensive Introduction to Photoshop Selection Techniques
Color Tools, Resources and Tutorials for Photoshopers
And as a bonus, here’s a link to the digital painting video tutorial I was commissioned to do recently for PSDtuts 
The image below is the final result of my tutorial:
