Here are several Essential WordPressâ„¢ plugins that you should find most useful. Keep in mind that WordPress future updates will often incorporate a plugin into their core functionality thus rendering the separate plugin unnecessary.
The first two are useful for frequently updating WordPress.
1. One Click Plugin Updater
2. WordPress Automatic Upgrade
3. No Revisions
Disables post revisions in WordPress 2.6+ to keep saved posts from clogging up your database. They must be removed from the DB by hand, but this plugin will deactivate the auto-save feature.
Removes the WordPress Version to prevent targetted attacks and version fingerprinting.
5. Simple Link Manager Plugin
by Teli Adlam
Teli Adlam is a good person to become acquainted with. If you buy one of her products you can join her support forum. ( It seems this product is no longer available. )
When you change the permalink URL of a post, you should provide a 301 redirect to it in case you have people linking to the old address.
7. WP tags to Technorati