Sadly, there is very little definitive information on Christopher Columbus.
His birthdate is known to be sometime between August 26th and October 31st, 1451. While many historians say that he is from Genoa, Italy, there is also evidence to the contrary: For example, he could not write in Italian. Other authorities believe that he was a Spanish or Genoese Jew, or that he was from Corsica, Portugal.
He was born to parents Domenico Colombo, a weaver, and Suzanna Fontanarossa. He went to sea at 14 as a pirate. In 1476, he fought against Genoa with the Portugese off of Cape St. Vincent. The ship he was on caught fire, but he was able to swim to the Portugese shore. There, he reached Lisbon.
After visiting Lisbon, he made journeys to Iceland. He believed that reaching Lisbon had been "divine intervention," and wished to make journeys far to the West; he believed that such a journey would bring him fame and fortune.
In 1478 he married Felipa Perestrello e Moniz, a daughter of a sea captain from one of Portugal's most influential families. For a few years, Columbus settled on Porto Santo in the Madeira Islands, where he gained more sailing experience.
In 1484 he began seeking a patron for his voyage, and after being turned down by John II of Portugal, he turned to Spain, where he was finally accepted by King Ferdinand and Queen Isabella. He was outfitted with the Santa Maria (a decked ship, 36m long), and two caravels, the Pinta and Niña. His crew consisted of 120 men.
Before reaching Haiti, his expedition made a stopover at the Canary Islands. In total, his expedition lasted about one month. Despite common belief that he endured a hard voyage, with devastating weather and a near mutiny, the weather was so clear that for days at a time sailors could converse from ship to ship. The only poor weather occurred at the very end of the voyage, when they already knew that they were near land. The "near mutiny" was nothing more than common conflict among the crew.
After many more voyages funded by Spain, fame and glory, Columbus died May 21st, 1506, in Valladolid, Spain. He died of gout, a form of arthritis caused by the rigors of the sea. He did not, as is suggested by many, die of syphillis.
I won't get into the many horrendous acts of Columbus, which you can read elsewhere. This writeup, instead, is meant to focus simply on his life, or what we know of it.
Some other common myths surrounding Columbus should also be noted: Firstly, by the end of the 15th century nearly everyone knew that the earth was round. The dispute was, in fact, the size of the circumference of the earth, which at that time was underestimated by a fourth. Although most people believe that Columbus was looking for an alternate route to India, we cannot be sure of this either. Kirkpatrick Sale, Columbus's recent biographer, also concluded that the truth will probably never be found.
Sources:
Encyclopaedia Britannica
Lies My Teacher Told Me, By James W. Loewen
Assorted websites