I love roaming around blogs. You never know when you'll stumble across a gem. This article from guest blogger Wendy Lynn Watson gives helpful advice and techniques on how to prune out the large cast of secondary characters that can quickly bog down a novel. I'd really suggest you hop on over and take a look. The blog itself also has a wide range of interesting articles with a focus on mystery writing - but a lot of the techniques can be used in any genre that has an element of clue-finding.
I tracked down the guest blogger to her own web-site and I'm glad that I did. Who wouldn't love a blog called Killer Characters? It's an absolute treat (though on a less practical note than the Mystery Writing Is Murder blog) as Killer Characters gives the various characters in her novels a chance to come forward and make blog posts themselves. Talk about a great exercise for getting to know your characters! It would also be a lot of fun for her readers as well.