Non-Profits are often faced with a unique challenge when redesigning their websites. Like other websites, they need to clearly communicate the mission of the organization, have a clear call to action, and engage their audience. We’ve selected 19 best non-profit websites that we think best accomplish this goal. Some of them use innovative design, some use multimedia, and some use humor. All of them accomplish the most important thing: When you leave, you know what they do and how you can help.The Acumen Fund has one of the most innovative designs we’ve seen. The homepage clearly tells their story, with sections on “What We’ve Accomplished”, “What We’ve Learned”, “Where We’re Headed”, and “How You Can Help”. Each section features information told in an infographic style to keep the visitor engaged throughout their entire story. And most importantly, the big black Donate button follows you the entire way down the page. We love this site.