I thought this Halloween would be easier for parents of Super Why obsessed kids. However, from the occasional comments to
this post from last year, and the flood of emails I get (in my treadmillista account that I basically never check) in response to the Super Why costume I guess I am wrong. I decided to take the time to detail out The Boy's Super Why costume from last year. Hopefully this can help someone else, who is looking for ways to make a Super Why costume for their Super Whyatt loving children.

Please note that I can't find the mask. The costume was in a pile of costumes in the basement play room, and as you know children don't always leave things in neat little piles. I suspect the mask is hiding somewhere in our 2-story plus finished basement house...I just don't know where.
The Shirt: this was made with green t-shirt material by my fabulous MIL. I found the logo on a coloring page printable from the PBS kids website, and then printed it on iron-on ink jet paper (you can buy the iron on ink jet paper at a variety of places including Target) and T ironed it onto the shirt.
Baby Blog Addict posted a fabulous clean jpeg image that you can use for this purpose, so check it out - I was emailing it, but I'm burnt out!

The shirt with the pants: The pants were made with the same t-shirt material. My MIL is pretty resourceful and didn't need a pattern to make either the shirt or the pants. This is great because I don't even know how to turn on our sewing machine (it is really T's not mine).

The back of the shirt has two small velcro strips sewn onto it, for easy attachment of the cape:

The shirt with the cape attached: The cape was re-used from a very old costume from T's childhood when he was Batman. It feels like a nylon blend of some sort.

The little shorts: These were also re-used from that same very old Batman costume. Same material as the cape...

The under shirt: The Boy had this already in his closet. It is a size 4 Lands End plain blue long-sleeved t-shirt.

The total package (minus the mask):

The mask - If I remember correctly we used thin foam board to get the basic shape, and then my MIL wrapped the green t-shirt material around it somehow. She used velcro strips at the end of strings of the t-shirt material so it could be secured around The Boy's head.
If you have further questions I will try to funnel them to my mother in law! I hope this helps someone.
Note: I updated the link to the Super Why logo, this new link should work. I apologize for not being responsive to questions/emails, but my current job has me swamped and just unable to devote time to a blog anymore. Good luck with your costume making!