Hi nightslyer,
Although i don't use photoshop, (I ones did but switched to free Gimp, and inkscape for vector design, which is alot of fun) i can really recommend this website: http://www.yourinspirationweb.com/en/category/design/
every now and than they have a theme like "restaurent website" or "urban" "grudge" etc, and explain what to look for how to achieve et cetera. It's great to give you an idea, and if i am correct they explain alot on tools and stuff. I must say Gimp has a great community that has a lot of tutorials. And if you want to try out inkscape (vector graphics I use that for most buttons /logo's and stuff 90% of my websites grafics) have a look here: http://screencasters.heathenx.org/ awesome detailed videos.
Hopefully you appreciate this although it's not photoshop. And the best thing it's free, and it seems you arent that bound to photoshop yet
-but i can really recommend those 2 above, easy to find tutorials, and inkscape will be a new addiction ones you get the hang of it and great for making sprites