Tony Iommi is the lead guitarist for the heavy metal bands Black Sabbath and Heaven & Hell. He invented heavy metal. His last name is pronounced (I - Oh - Me).
Prior to forming Sabbath, Iommi worked in a sheet metal factory. On his last day on the job, a machine sliced off the tips of his middle and ring fingers on his right hand (he's left handed and frets the guitar with his right hand). What a shitty way to end a job. He showed off his badassery by making his own prosthetic fingertips and relearning to play with them. Many of us would have wallowed in self-pity, but Iommi simply manned up and fixed the problem himself.
With William "Geezer" Butler, Bill Ward, and John "Ozzy" Osbourne (yes THE Ozzy Osbourne) he formed Black Sabbath. They were originally called The Polka Tulk Blues Band, later shortened to Polka Tolk. Realizing their band name sucked, they changed it to Earth. Thankfully, common sense made Geezer Butler comment how odd it is that people will pay to be scared while watching people waiting in line for the film Black Sabbath. They then changed their name to Black Sabbath from either the aforementioned movie or a song that Ozzy wrote (or both). He briefly left the band to play with Jethro Tull but returned to Black Sabbath shortly after. In December of 1969 they recorded their debut Black Sabbath. It is regarded as the first heavy metal album. Critics bashed them, but it only gave them free publicity.
They then recorded what would be their most sucessful record Paranoid. This record has their most well known songs on it such as War Pigs, Paranoid, and Iron Man. Every aspiring metal guitarist is required by law to learn the main riff to Iron Man. Also, Metallica played Iron Man at the band's induction into the Rock N' Roll Hall of Fame.
Next was Master of Reality, which featured Iommi detuning his guitar three semitones or half-steps down, making the album sound very heavy. Their next album was called Vol. 4 and is notable for being a tribute to cocaine (and my favorite Sabbath album). It was originally entitled Snowblind, but the lame record executives made them change it. Some songs such as Snowblind and Supernaut are a reference to cocaine (and they are awesome songs). Fun fact: Frank Zappa said the main riff to Supernaut was his favorite riff. Sabbath Bloody Sabbath was their next album, and is regarded as their last good album with Ozzy. Metallica covered two songs off of this album.
Then came Sabotage which featured the songs Hole in the Sky and Symptom of the Universe (was used in Brutal Legend!). Technical Ecstasy came next and had a cover which was supposed to look like two robots fucking. This album had the awesome song Dirty Women.
Then they recorded Never Say Die and it reportedly blew. The title track was used in Brutal Legend, though. Then Iommi fired Ozzy for being too crazy. Then Iommi hired Ronnie James Dio as their new singer. They recorded Heaven and Hell (great album), The Mob Rules, and in a reunion in the early 90s, Dehumanizer. After The Mob Rules Dio left and Iommi hired Deep Purple singer Ian Gillan. When Gillan left, Iommi replaced him with singers who aren't worth mentioning (look it up yourself).
Iommi has played with James Hetfield and the surviving members of Queen at the Freddie Mercury Tribute concert.
In the late 90s the Ozzy era Sabbath reunited and released the live album Reunion which was a live set of their early material. In the early 2000s, the Dio era Sabbath reunited under the moniker Heaven & Hell and recorded The Devil You Know in 2009.
Iommi almost exclusively plays Gibson SGs. While recording Black Sabbath he was using a Fender Stratocaster, but a pickup broke on it and he switched to an SG and has used it ever since.
He uses mainly a Tychobrahe Parapedal wah pedal, which aren't manufactured anymore. If you wanna read up more on his gear look here (I'm too lazy to list anymore).
Little is known about his personal life. What is known is he has a son (don't know his name) and a daughter named Toni-Marie. He was married around 3 times. He was briefly engaged to Lita Ford. Wikipedia surprisingly has little information on his personal life.