If you haven't yet, you will...it's just a matter of time. :)  When you do, Getting good with Google Reader is a very valuable overview of the key keyboard shortcuts that you'll need to make the most of Google Reader.  As with most peeps, these are my keys:

j - next
p - previous
v - view in window
ga - All Items
SHIFT-n - next folder
SHIFT-o - open folder

I'll definitely be trying to get used to some of the others outlined in the aforementioned article as well.  The gu keyboard shortcut is definitely the snazziest that I didn't know about.  I think Reader is the most Ajax-irific app I've used thus far, how 'bout you?