This essential source lists every coin from nearly 50 countries, each with its current price, and hundreds of photos for easy identification.
This edition also
• Tips on buying, selling, and grading • How to collect mint errors and oddball world coins • An up-to-date market review • Trends in collecting and investing • Listing of world coin associations and organizations
I recommend it for the simple on the fly look-ups. I use it mainly for the Canadian section. It doesn't list much world coinage, and the countries it does are pretty limited.