James Cohen has a recent post to his blog looking at a way you can avoid some of the character encoding problems in PHP that can come with working with multiple character sets.
Character sets can be confusing at the best of times. This post aims to explain the potential problems and suggest solutions. Although this is applied to PHP and a typical LAMP stack you can apply the same principles to any multi-tier stack.
He includes a "boring history" session (and recommends skipping if you just want the good stuff) that talks a bit about character sets and their history in computer system handling. All that said, he recommends using UTF-8 to ease your character encoding woes. He talks about configuring your editor to support it, making sure your browsers understand it and setting up your MySQL database connection to use it.