Layers Palette (CS3)
Layers Palette
At the bottom of the palette, from left to right is:

The chin: link layers button (must select more than one layer to make it active.

FX: Layer Style button

Box with Circle inside: add layer mask

Half black circle: Create new fill or adjustment layer

Folder button: create new group

Turning page button: create new layer

Garbage can: Delete Layer

If you can't find the layers pallet, go to Window>Layers and it should appear. We are using Photoshop CS3. Yours may look a little different