Yes.

Simplicity is key.

3 big blocks 338x280 ON THE LEFT of the site.
Top (above fold) , Middle, Bottom

2 Link Units, one all the way on top, one bottom.

If you scroll through your site, always make sure there is no "blank" space without ads anywhere. First ad block above fold, other two below fold.

No distracting menus or anything - you can also leave default AdSense colors.

From google themselves: xxx.google.com/adsense/support/bin/answer.py?hl=en&answer=17954

change the xxx to www - IW wont let me post links yet