Useful links
Football Uniform - A japanese page with many match pics of many different shirts of the world, all of them from national teams.
Old Football Shirts - An UK site that works more or less like a football shirts wikipedia. Watch out to what you can find here.
Kotologo - This page has the logos of almost every team you can think about. You will not find shirts here, but in case you need any logo, this is the place you need to go.