If you want to make a quick image gallery, you could upload a set of similarly sized images to a folder, adding titles to them if you want to have captions for the images. Then got to the 'Display' tab for the folder and select 'Thumbnail view'. The folder will show similar to that below. If the images are not similarly sized it will still work fine, but it won't look as neat.
A large number of images will be batched into groups of 12 for easy viewing. The above screenshot is from http://www.nanomanufacturing.eng.cam.ac.uk/NanoScapes/CNTScapes