How to make sure your images are web-friendly
What format?
MiniGallery likes JPG images. JPGs are small and efficient, which is what makes them so perfect for using on the web. Most digital cameras save directly to JPG, but if yours doesn't then you can easily convert your images to JPG using any good image editing program. You can even get programs designed specifically to batch-convert a whole load of images from one format to another. Just Google 'image format converter' and see what grabs your attention.
What size?
There are two interpretations of 'size' that should be addressed: the size of the photo and the size of the file.
The photo size refers to the dimensions of the image in pixels. The more pixels, the higher the resolution, the bigger it will be, and the more detail you will see in the image. For printing, you want as high a resolution as you can, so that you get a high quality result. However, on a computer screen you can use much smaller images and still have them looking fantastic. Unless you intend people to download and print high-resolution photos, you can easily get away with scaling your photos down to 1024x768 pixels, which is fine for viewing on a computer screen or using as a desktop background.
The file size is where it all gets interesting, though. JPG images are compressed, which means that it uses a clever algorithm to squash the image down to reduce its file size. An uncompressed photo can be very big, several MB, which would take a long time to download. A default JPG would be much smaller in file size, and you're unlikely to notice the difference when you look at it. Of course, you can over-compress an image, and then it starts to look awful - it will develop JPG 'artifacts', which are rectangular irregularities in your photo.
As a general rule for setting up your images for optimum efficiency on MiniGallery, aim to save your images at 1024x768 and a JPG compression value of about 60%. That should ensure that your photos look great but download quickly. This also speeds up the scaling process for generating thumbnails and previews, so it's also kinder to your server!
What orientation?
Whatever you like. Traditionally an unmodified photo from a camera is of a 3:2 ratio, and either landscape or portrait. MiniGallery doesn't mind what the dimensions of your photo are. It can be a conventional 3:2 ratio, a widescreen panorama, a square... whatever you need.