Two CodeProject articles on Creating multilingual websites are great sources of information, and actually mirror the way I've also approached the problem with my own projects.
But something I hadn't read much about (yet) is Using Resources for Localization with ASP.NET 2.0 (Fredrik Normén's) which was linked from CodeProject. The approach in ASP.NET 2.0 still seems a bit clumsy to me - still no "built in" way to have site-wide localization management, nor a simple cross-over between localization of static elements (such as labels, text, html elements) and database-resident information (product names, news items, etc). You could argue that there are a multitude of possibilities and that Microsoft can't address all possible permutations -- but why not at least offer a basic solution, like they do for Authentication, Personalization, MasterPages, etc???