At Simpl app, we believe that images are super-important for your web pages. That is why on a text page or news item, we limit the number of images to just one. This is what's known in the business as a "hero" image.
Why did we do this? In one word, it's all about focus. Simpl websites are designed to be clutter-free for your website visitors. That's why there's plenty of "whitespace" (not always white) in all of our website themes. This gives your content, whether text, images, links or videos, room to breathe. As a result, your visitors can focus as you intended, with none of the distractions of most other websites - banners, ads, gratuitous animations etc.
So, back to your hero images. This should really go without saying, but we are duty-bound to say it anyway: choose your image carefully. Learn to spot the key components of a great image: clarity, simplicity, contrast, interesting subject matter, proportions, dimensions, colour balance and so on. Make full use of stock photography websites where quality images can be purchased extremely cheaply. Take time to find the right image that sends the right message for your audience. Don't rush this.
It's so important that we'll say it again: choose your image carefully.
And of course, for multiple images, use a photo gallery page or a news page with multiple items. In which case it's even more vital to choose pictures wisely...
EXTRA 1: For added SEO benefit, name your image file using keywords appropriate to that image, before adding it to your website.
EXTRA 2: In addition, make sure your image has a caption. Search engines like Google love to see a bit of (relevant) text.