When I told my brother I was making this page, he very helpfully supplied me with the following list. It is not extensive, but it's a lot better than I could have done alone! (I left all his comments intact, as a service to you. Enjoy. ;^)

I lifted this from everything2.net. It was written by Habakkuk (go to everything2.net and do a search for 'The Penguin'). I don't mean to steal it but it's a very good summary of the comic book Penguin's history (although I thought Miranda was his aunt not his sister?)

A villain first published by DC Comics. The Penguin first appeared in Detective Comics #58 in 1941.

Oswald Chesterfield Cobblepot's father was the owner of a shop that sold birds. He died at an early age from pneumonia, which Oswald's mother was convinced was caused by his father going out in the rain without an umbrella. From that point forward, young Oswald was forced to carry an umbrella with him whenever he left the house. This along with his lack of height and being overweight caused Oswald to be the target of a good deal of mocking from the other children. They nicknamed him Gobble Gobble and penguin because of his appearance.

Through the years, Oswald and his sister Miranda helped their mother to run the bird shop. Oswald became quite attached to the birds and sought solace in them when he was teased by the other kids. Through this, Oswald became an expert in all there was to know of birds, so when he went to college to study ornithology, he found he was already better versed in the study than his professors.

Soon after Oswald graduated, the courts seized the bird shop and the birds because of back taxes that were due. As Oswald watched the only friends he had ever known being taken away by the law, he vowed to oppose the law from then on and become a thief. When he attempted to carry out his plan, he was mocked by other criminals and called the Penguin. Oswald again decided that he would show them that he was not to be mocked and that he would make his umbrella a thing to be feared, not derided. When next he was seen, Oswald was dressed the part of a penguin, in tuxedo and tails and carrying an umbrella that concealed a .45 caliber gun. He also called himself the Penguin.

The Penguin's crimes have often times brought him in conflict with Gotham City's defender, Batman. The Penguin's plans usually involve bird related themes and he often employs trick umbrellas that do such things as act as shields, spray gas, can be used like a helicopter, or give an electrical charge. Despite his appearance, the Penguin is trained in boxing and can be a tough foe in a fight and has also shown himself to be very agile.

The Penguin has been portrayed on both television and in the movies. On the Batman television series, the Penguin was played by Burgess Meredith, while in the second Batman movie installment, the Penguin was played by Danny Devito. In the movie, the Penguin's origin was changed to make him the deformed son of a wealthy socialite who was abandoned as a child.

Links to other specifically comic-related Penguin sites:

The Penguin - Fowl Play

A good overview of the character's history in the comics.

Batman vs. The Penguin

A review for an apparently dumb comic. But, history is history!

Dark Victory T-Shirt

Shows how they depicted the Penguin in the Batman: Dark Victory series.

The Unofficial Guide To the DC Universe

If you type "Penguin" into the Google search you'll get the synopses for a ton of comics.

Comic Cavalcade

They sell a wide variety of used comics, if you're looking for any.