Well I have CS so im guessing its about the same so there is basically how you can configure PS grids for spriting:
To change the grid size go to:
Edit>Preferences>Guides, Grids & Slices
Then change "gridline every" to:
16 pixels for tiling
1 pixel for general spriting
or w/e to suit your needs
Then make sure View>Extras (ctrl+h) is checked along with View>Show>Grids (crtl+')
If you want things locked/snapped to the grid (especially useful in making tilesets) make sure View>Snap (shift+ctrl+;) is checked
Then when you start spriting you want to use the pencil tool since it is square and doesnt do any funky, AA, Circular crap that the brush tool does. The pencil tool should be found by clicking and holding down the Brush icon on the toolbar then click the pencil (unless CS3 is different)
Remember, above all else, layers are you friend so you can build up your sprite without messing up something you've already done!
Edit- If you need any other pointers on how to work PS just PM and I'll see what I can do for you.
- The friendly neighborhood PS Angel