Is there anything in particular that you are looking for? Most international operators are going to use information provided through a flight planning/charting service such as Jeppesen or Universal Weather.
There are some basic guides out there such as the UV-Trip International Book and
Acu-Kwik books.
There are also some basic sites that I use for preliminary planning, but not for navigational/regulatory purposes:
NBAA International Airports Database (Members only)
International Flight Information Manual
There are a few others that I have bookmarked on another computer and can't think of off the top of my head- I'll try to remember to post them later. ~J