This is the part that can get expensive. Most likely, some member of your congregation already has such a program and will be happy to help with the website. Corel PhotoPaint is compatible with just about everything. Also extremely overpriced, imho. It's definitely the choice for those on a tight budget.
Graphics are usually the culprit when a site takes forever to download.
No one wants to hang around for 4 minutes just to see your pretty border. Keep 'em small and simple. Always compress images GIF files compress images by reducing the number of colors in a graphic. This works well for most images except photos and those with graduated fills. GIFs can also be assigned a transparent color, which will not show on a webpage.