Writing articles and copy for an online audience is different then writing for print, and the following links offer sage advice for penning good web copy.
An overview of where RSS falls in the world of copyright. A nice link to have if you ever find someone using your feed without permission, this clues you in to what really is and isn't allowed.
An online spell checker that can enhance any text area with extras like a dictionary, this bookmarklet looks to be very useful. Read a full review over at Solution Watch.
Mark Boulton gives an overview of when to emdash, when to endash and when to hyphen.
Some common spelling and word use mistakes. It could be worth noting these types of error in a style guide.
Ever written a nice piece of researched copy for a client and had it ripped off? I bet you have and just don't know it! Here's the service to help you out: Copyscape finds sites that have copied your content without permission, as well as those that have quoted you.
I wonder where they found their inspiration for that logo ;-)