15 Golden Principles of Visual Hierarchy | http://www.designmantic.com/blog/infographics/15-golden-principles-of-visual-hierarchy/
Image File Cheat Sheat: When to Use JPEG, GIF and PNG
Social Media Image Size Guide - dimensions for the area to display personalized images that fit perfectly on Facebook, Twitter, Google +, and Pinterest
Print vs. Web
Understanding Logo File Formats -- Great info explained in an easy to understand logical way! Know which file is used for what and what you should use & get from your Designer! :) Great for referencing and learning....