We use a variety of (mostly free) WordPress plugins for a publishing website. Instead of creating all kinds of tools in our own plugin, we chose to use WordPress because there are so many free plugins already out there.
Here are the ones we use, with the most important marked with an asterisk :
Admin Post Navigation : Adds links to navigate to the next and previous posts when editing a post in the WordPress admin.
Category Order and Taxonomy Terms Order* : Category Order and Taxonomy Terms Order.
Easy Digital Downloads : A simple e-commerce system that lets us sell books. It takes a little bit of work to get it set up right, but it is well made.
View own posts and media library items only : This is useful if you have more than one user on your WordPress website, and you don’t want them sharing pictures!
Imsanity : I would like to recommend this plugin, but I have require resizing to done using rounding. This may sound obscure, but the correct size for a 3:2 photo is 1024×683 pixels, not 1024×682 pixels, and some book templates expect a 683 pixel picture. That said, if it is good enough for you, it us a good plugin to resize those huge digital camera JPG files to something reasonable! Be sure to use JPG 90 setting, because the JPG 80 isn’t very good (even thought it should be…they might be using a low quality JPG converter).