Joel Spolsky has posted an interesting summary of general understanding problems with encodings, character sets and Unicode in particular. Worth a read for every programmer.
His own weblog is a good example on how to do it right. Many people contribute to his web site by actually translating his content into various languages. So far there are 29 languages available and this a good test to see if your browser setup does it right. Wiith Safari and OS X everything displays like a charm. No missing glyphs, everything beautifully aligned. I love this machine.