So you decided to build your church website in WordPress! Congratulations on making a wise choice, and unless you have a budget of 10k or larger, you can grow with WordPress for years to come. Churches from 25 to 25000 could easily use WordPress since it is easily customized and is the largest open source PHP platform on the web today. So you perhpas you bought a custom theme for your site or custom designed it and now you need some easy to customize function. I have listed some important plugins that works well for churches as of version 3.9.2
A very powerful cache plugin that helps with the overall performance of your website. It allows you to simplify how a browser pulls up CSS, HTML, JS, PHP and other objects each time your website is brought up in a browser. I always recommend a cache plugin of some kind for churches because of the large amount of information, video, audio and graphics.
Out of the box, the free version can add maps, categories and media for your events. It comes with a calendar, lists, and and widgets for your church events. With a little know how the plugin is very customizable to make your events look the way you want. I actually use this plugin for our church and we can add events based on each campus so it will only show on the campus page it is appropriate for. It is compatible with BuddyPress, Multisite and Google Maps. If you decide you need to take payments for events, upgrade to the pro version for $75 or $150.
With many churches deciding to go parallax and responsive, more and more church sites are very visual. This means that your website may lack the amount of text content websites used to have. Making sure your images are properly titled and have important ALT tags is vitally important to your church website's SEO quality. SEO Friendly Images allows you to set your default SEO setting for images on your site. You want proper ALT tags so Google and other search engines will have a proper description of your images.
This plugin costs a little bit of money but it is worth the investment of $75 or higher. Keep an very detailed archive of your online sermons both in video and audio formats. Set it up so viewers can choose to watch sermons based on speaker or series name. This plugin also allows you to setup an iTunes podcast for your church. If you are looking for a robust and customizable solution for online sermons, look no further.
This is my top pick for any WordPress website! Your church will benefit greatly from this plugin that has some very advanced SEO tools built into it. Every page or post you create is graded based on a focus keyword or key-phrase. It comes with great default settings but it gives you full control on what search engines can see on your site. Some of the greatest features include XML Sitemap generation, edit the "unseen" robot.txt file, set default social sharing information for each page and it is multisite compatible.
There are quite a few not on my list of course, but would love to hear what plugins you use for your church site.