I'm currently using WP 1.5 for my blog which is located at http://blog.permagnus.com/ . I know that 1.5 is quite obsolete especially after those bugs discovered so I'm planning on upgrading the software to 1.5.2.
My WordPress is somewhat modified a littlebit. Add some plugins and some design. Is there any specific matters that I have to care about? Is there any step-by-step upgrade guide that I can read on?