I am forever looking for the correct sizes for envelopes, facebook headers, twitter logos, etc.
You may think, why is this important? Well, let me tell you. When uploading a general image for personal pages, you can get facebook or twitter to crop, resize and center your image. But if you are a business, you want to put on your best face. Do you really want your image to be distorted, or worse, pixelated? When you start out with the correct sizes, you can ensure a beautiful piece that tells prospective clients that you and your business are professional.
I came across this article last night that I think is genius! And by posting this, I won’t lose the link. This is a great tool for just about every social media program that we are using today.