When you start creating a Google Site you should chose a fun Theme (this one is called "Vision") and color... then in the banner add an image, and you can click Insert > Layouts for a nice layout like there to add some pics. Here's a simple layout:
Subtitle for the image you uploaded.
Subtitle for the image you upload.
You can drag a text box next to your map to add contact details.
Email: mybusiness@gmail.com
Phone: 555-555-5555
Address: xxxxxxx, San Francisco
Here I've added another text box. Some business sites are just a single page, since that's all you need.
A more typical site might look like:
The contact page is most important... what you chose depends on your business, but make it punch and fun - not huge amounts of text.