Uploading a photo to the design system is probably the hardest part of designing your magazine cover. For the web-savvy it is no big deal but if you're not all that familiar with digital photography it can be frustrating.
You need a photo with a high resolution - we recommend 1024 x 1280 and the minimum acceptable width is 600 pixels. Just because it looks good on your computer screen doesn't mean it will look good when printed at 8" x 10" (or on a poster at 16" x 24"). Photos from Facebook or that you download from a friend's online photo account won't be at a high enough resolution. Check your photo's resolution by right clicking on the photo and looking under properties (you can also open it in a photo application like Microsoft Office Picture Manager or Paint to see the properties/attributes).