Here's for Japan: http://www.customs.go.jp/english/c-answer_e/customsanswer_e.htm (it's the general FAQ page).
For some example of tax rates, here it is: http://www.customs.go.jp/english/c-answer_e/imtsukan/1204_e.htm
On top of that, there's also the 5% consumption tax and sometimes a handling fee (I only have two experiences of paying customs duty & tax: once with Fedex and the other was a USPS Priority Mail package; for both I had to pay around 200 yen of handling fee)
Thanks for that. It made my Fedex Bill easier to read. I just got charged tax for reimporting my bag into Japan, after it was repaired by Chanel USA! But the fee is probably not worth the hassle of challenging it.