Layer effects was new in Photoshop 5 and makes a lot of third party plugins unnecessary. Here's a brief overwiev of these effects. Be sure to check out how to use them in the "glass spheroid" tutorial.
Dropshadow
Innershadow
Inner bevel
Inner Glow
Outer Bevel
Outer Glow
In Photoshop 6.0 there is this new "application" called layerstyles, and it facilitates your work monstrous.
With one single click, you can achieve very cool effects like this one below.
More Tutorials: 
