Akismet comes standard with WordPress, and it’s absolutely necessary. A high-traffic blog will generate a vast amount of spam, and this drops it to a trickle. All WordPress installations should use this!
All in One SEO Pack
This excellent plugin handles the primary tasks related to optimization of your pages for the search engines. Titles, keywords, etc. Very comprehensive.
I am personally a fan of Highslide for displaying images and galleries, but this is very low overhead: Thickbox is already built into WordPress, and this enables support transparently when you insert images into posts and pages. Hard to argue with the ease!
CMS Tree Page View
If you use a lot of pages in your site, then this plugin is really handy. It provides a collapsible outline view of the pages in your site. You can expand and contract any branch of the outline by clicking, and can open the editor for any page at will.
Contact Form 7
Easy to use and versatile plugin for creating contact forms. It’s easy to have as many forms as you want. Plugins exist that enhance CF7 to save the results in the database instead of emailing the results. Very elegant because of the ease of use.
Simple to use: plug in your Analytics ID, and you’re ready to go. You can tell it where to place the code (head or foot), or just use the defaults.
Google XML Sitemaps
Generates an XML sitemap of your site every time you make a change, and publishes the change to the major search engines. Lots to tweak, but it works pretty much right out of the box.
I’m relatively new to this plugin, but it opens up some great possibilities. Basically, you define named fields along with the HTML code for using them. When composing a post or page, you can ask to insert any of your predefined snippets. After choosing one, it will prompt you for the named fields, and then insert the modified HTML text into your post. This table of plugins was created using a pre-defined box layout, with Post Snippets to prompt for specific fields. It seems like a nice way to reduce formatting errors when typing new stuff into a page, especially for non-technical people using the WordPress backend. The WYSIWYG editor gets confused occasionally, and non-techies occasionally whip the underlying HTML into a frenzy—this may provide an easy way to maintain the formatting.
Extends the TinyMCE editor in a lot of ways, making the thing usable. The best enhancement is a dropdown menu for classes defined in your theme, allowing you to style spans of text.
A simple plugin for putting ads in your site. The neat thing is that it drops custom code into your pages wherever you want, whether containing ads or other code. You can set up multiple ads to rotate in the same place, of course. It also tracks impressions (but not clicks). This basically gives you a shortcode that can drop an arbitrary unit of code into the given location.
Absolutely necessary to have this. It lets you schedule backups for archiving or emailing, schedules optimizing the MySQL database, and lets you run limited SQL queries.
WP Simple Paypal Donation
I’ve used this simple interface to making donations to an organization using PayPal. You can see this in action at www.kelleyhousemuseum.org.
WP Simple Paypal Shopping Cart
I’ve used this simple interface to the PayPal shopping cart in several places. You can see this in action at www.kelleyhousemuseum.org.