Cancer Quilt...

[clusterfuct.livejournal.com]

I need help desperately! I volunteered to make a 12 1/2" x 12 1/2" unfinished square for my cousin's cancer quilt and I have no idea what I'm doing! My aunt said something about the blocks being set "on point," but I'm not sure what that means? I bought three different materials, because what I want to do shoul come out looking something like this, but I'm not sure how to accomplish that...Can someone help me?!