Download them all, delete the really bad ones right away. Sort by location, subject, date - then every couple of weeks I run through them again and delete more. As my shots get better (well, I think so!), I go back and delete more. I end up with 5-20 per 100 as keepers.
My plan is, when/if I learn PhotoShop, to run through again and see if they really are keepers. Then maybe, I'll print something seeing I have a new never used printer waiting.
I read once that if 10% of your shots are keepers, you're going damn good. Of course, my idea of a keeper and a professional's idea are worlds apart! But then again, you never know whan a duck shot wil come in handy so you can't delete them all. 