Posting sermons online are a great way for potential visitors to your church to get a taste of the personality of the rector/dean. Sermons are one of the top searches of people who are visiting your site and are often the most visited pages for churches who make their sermons available online.
If you are unable to record sermons every week due to inability to find volunteers or staff to take this on, don't worry! Start small and make the commitment to record a few sermons. Present the sermons as a sampling of your ministry. If you are able to record sermons weekly, consider providing opportunities for keyword searches, searches by topic, or search functionality even by liturgical season.
Your website probably has an integrated sound file feature. Research what works best with your website as integrated already into your Content Management System (CMS) by googling your CMS name and "audio player." If you are unable to locate any information about integrated audio players, you can also embed code from soundcloud.com or sermon.net. If you have a Wordpress website, consider using the Powerpress plugin from Blubrry. These integrated systems and other resources often have tools for podcasting as well. Do some digging around and find an option that works best for you!