I agree with everything Nukemegood has stated.

I feel that spelling out every individual item in the quick tips is unnecessary, I would suggest only listing the prerequisites only if you do not finish the item right away, or if there is a certain reason you chose one prereq first over another. It will definitely make it easier/quicker to read.

You have Thornmail twice in the build. Are you saying your build calls for two thornmails, or buy one, sell it and buy another at the end? That may need clarification.

As for masteries, I would look into possibly grabbing nimbleness, putting 4 points into evasion and not worrying about the amazing buff nimbleness can give seems counterproductive what you're trying to accomplish (especially because the movement speed buff with help the powerball). My personal preference is to max awareness as well to get the most potential out of exp gained.

I won't downvote as I can see you just joined and this is your first build. Just trying to offer some tips.

Well, the ideas are all there, but I think you could use some more info. The chapters, and overall the guide, seems to have rushed through all of its points, and not really explained anything...
Also, your skill sequence is impossible- it only has three points in Puncturing Taunt, and six points in both Powerball and Defensive Ball Curl... You might want to pay more attention to your guide.
Also, you may want to add in some more eye-catching media, like a video or some pictures. I think it would really improve its readability.