I used Microsoft Word, and saved stuff with the .pdf extension they wanted it in. I'm using Word for the whole program, only 4 courses left. I have never used a Mac, so maybe someone else has tips on that.
You can do it either way. I found it easier to draw the diagram/make the model, take pictures with my phone, email them to myself, and then insert them into the paper. Passed all 5 tasks on the first try, just make sure to follow the rubric. The video guides were extremely helpful as well. And the diagrams don't have to be textbook worthy, just enough to show you understand the concept.