I recommend checking out Corkami's articles/posters:

https://code.google.com/p/corkami/wiki/PE

https://code.google.com/p/corkami/wiki/PE101

https://code.google.com/p/corkami/wiki/PE102

It also has a section about the minimal size: https://code.google.com/p/corkami/wiki/PE#minimal_sizes

Modern Windows versions refuse to run the 97 b and 133 b files from the linked article.