Alright, this is my first instructable so go easy. In retrospect, I should've taken pictures while I was making the costume, but everything is self-explanatory.

Supplies

-Blue Long Sleeve Shirt-$6 at Walmart
-Blue Sweatpants- $7.50 at Walmart
-Red Single Panel Curtain-$7 at Walmart
-Pack of "Neutral" Felts-$4 dollars(I think) at Walmart
-4 pack of briefs(with red)-$8 dollars at Walmart
-Liquid Stitch or other fabric glue-$3 dollars at Walmart
-Velcro dots-$3 dollars at Walmart
-Red Socks-$5 dollars for two pairs at Walmart
-Scissors-Free
-Reference Pictures-Free
Total-$43.50

This whole thing took me about two hours total construction time. Most of which was spent on the insignia. The rest was trimming the cape.

Step 1: The Insignia

This is a matter of finding the Superman insignia you like best and copying it.

First, copy the shape of the insignia onto your yellow or gold felt like I did (incorrectly I might add, but its artistic liberty now).

Then, cut the shape out in both the red and yellow(gold) felts by folding the two together and cutting it out, like a Valentine's Day heart for superheroes.

Next, copy the S onto the red felt you have now cut to shape, this includes the borders. Once that is done cut out all of the odd shapes that don't resemble a border or an S. I would suggest using a craft knife or similar tool, but I only used scissors.

After the logo is cut out glue the two together with a liberal amount of Liquid Stitch, don't worry about the mess. This stuff dries clear and wipes off easily.

Step 2: Placing the Insignia.

This step is simple. Put on your Blue shirt and center the insignia on your chest. Once it is in a place you like, attach it with liberal amounts of liquid stitch.

Step 3: The Cape

This was perhaps the hardest part. Take your curtain, which should be about 58 inches long if you bought the same one I did, and drape it more or less with the corners over your shoulders. The corners should hit about your collar bone. Take you Velcro dots and place them on the curtain corners and on your shirt where you want the corners to hit. Also place one at the shirt collar at the back of your neck to pick up the slack. Those of you so inclined may trim the cape shorter as I did, and perhaps contour it to your shoulders, unlike what I did. You may also choose to forgo the Velcro and sew the cape to the shirt, if you have the ability.

Sorry, I don't have an image for this part.

Step 4: Dressing the Part

This is easy and fun. The blue shirt goes over your undershirt( or lack thereof)
The pants go on your legs. Then the red briefs and socks. If the socks have logos make sure they are on the bottom of your foot.

Step 5: Hair (Optional)

Comb or brush your hair to the preferred side(I prefer right) with either gel or mousse. Before it dries, be sure to get a dangly hair in the middle of your forehead. You may choose to do this ala John Travolta in Grease.