Do I need to be familiar with HTML in order to edit or add images and/or content to my Joomla site?
No. This is what makes Joomla CMS so popular. Clients can add their own articles, updated information and images to their website. If you can write and send an email, you can edit and add your own content to your Joomla site! If you prefer to use HTML, you simply click on the HTML button and add code of your choice.