If you have a file that is in one of several standard graphic formats (like JPEG, GIF, PICT, etc.), use the Insert menu/Picture/From-file and select your file. The image will appear on your document with handles. To resize image put curser on corner, hold Shift and drag photo to size desired. *If you do not hold shift, this can cause the image to be distorted.
Photos need to be high resolution photos of 150dpi or higher.
High Resolution = No Blur Low Resolution = Blur
When you insert your image to the PowerPoint, you can check to see if the image will be high quality by checking the poster at 100%. Go to the View tab, click Zoom.
This is what the poster will look like when printed. If the photo is blurry, pixilated or distorted at 100%, it WILL be that way once printed. If it is not high quality you need a new graphic.