Smashing Magazine have published an article aimed to developers about website maintenance. This post gathers a bunch of tips we all know about and some more we would better use on a regular basis.
The most interesting thing to me is that it points out that maintenance is not only about content review, error fixing or analytic reporting. Code needs to be maintained as well! It takes a few things such as regular reviews and optimisation, proper comments and also CSS3 and HTML5 enhancements. Worth reading: Website Maintenance Tips for Front-End Developers.