Deadpool was created by Rob Liefeld and Fabian Nicieza and he first appeared in New Mutants #98 in February 1991.
He isn't really a super hero per se. He is more along the lines of a mercenary.
His real name is Wade Wilson.
He has a strong healing factor, much like that of X-Men's Wolverine although his was artificially implanted by the Weapon X program. He is also immune to psychic and telepathic attack.
He also has the ability to teleport, however, this is not a power, it is mechanical in that he owns a personal teleportation device.
His origin is that he was dying from cancer with the Weapon X product offered to cure him by implanting his healing factor.
He is an expert in martial arts and is an expert swordsman and marksman.
A loose adaption of the Deadpool character appears in the film X-Men Origins: Wolverine and is played by Ryan Reynolds. Supposedly there will be a Deadpool movie although the producers have said that it will be a "reboot" of the character and that we (the audience) should ignore the Deadpool from the Wolverine movie.
Here are some links where you can read more about him: