If you want to create a digital slide and post it on one of the digital boards on campus, there are specific guidlines to follow and an online submission form. A brief version of the guidelines follow. Click here for the a complete list of guidelines.
Digital slides must be in .jpg, .gif, .png, or .avi file format. .avi is a video format.
The slide must by 726 x 543 pixels.
Images in your design should be at least 72 dpi (dots per inch).
It is your responsibility to ensure that
a) any images used in the display design are either copyright-free, or
b) you have obtained written permission to use the image.
To get started, open a new file.
In the New box, choose a Custom preset and make sure your Width and Height units are set to Pixels instead of Inches. Then enter 726 for the width and 543 for the height of your new canvas. Click OK.
Your canvas will look something like this.
You can now begin adding layers to the canvas. It's a good idea to use a separate layer for each element: one for the background, one for each image, one for each line of text, etc.
To place an image from your computer onto the canvas, go to File >> Place.
Navigate to the image you want to add to the canvas and click Place.
Photoshop will put the image in a new layer for you as shown in the Layers panel on the right side. The image will also be selected with the X over it so you can move and resize it.
When you have the image where you want it, click the Move tool as shown. Then click Place.