As a front end developer, it was very useful for me to know Photoshop for basic image creation and manipulation, especially before the days that we had in-house designers.  You know for like putting your co-worker’s head on various photos like a giant blue unitard.   Anyways, I learned using a book and just basically playing around with the tool.  Since those days though, there have come out a couple of sites that make it easier for people to learn and also to expand their skills.

For basic to intermediate users, I would check out “You Suck At Photoshop“.  There are two seasons worth of videos, covering different topics such as layering, cloning, stamping, distorting, masks, etc.  I find the guy pretty funny which makes learning photoshop less monotonous and boring.

Another place that I feel has excellent tutorials (but may be for the more intermediate and advanced users) is PSDTuts.  Most of the tutorials are written step by step instructions with images, rather than video, but I find them descriptive enough to follow along.  (I should add they do have videos too)  The pictures are also helpful for any details that they might have left out.  This site also offers alot of icon, brush, and filter freebies, which is nice.