Claudius dressed as a hero (from the Vatican Museum)
Claudius was born in 10 BC in the city of Lugdunum in Gaul (modern Lyons, France). His mother was Antonia Minor, Mark Anthony's youngest daughter with Octavia, and his father was Drusus, Tiberius' younger brother. Because his mother was the emperor Augustus' niece, Claudius was related to Augustus, and his uncle Tiberius was in line to become emperor, so Claudius was an important person even as a child. He had an older sister and an older brother, Germanicus (who grew up to be Caligula's father). Claudius' father died suddenly when Claudius was only a year old, and he was raised by his mother Antonia and his father's mother Livia. They hired the historian Livy to teach him history.
Claudius had a disability, so that his mother thought he would not be able to be a politician. He stammered, and his head shook, and his knees were weak, and he slobbered when he was excited. He may have been sick with a rare illness called Wilson's Disease, which can also make people psychotic (crazy) - Caligula may have had it too. Or it might have been cerebral palsy.
For more on the Julio-Claudians, check out these books from Amazon or from your library:
Classical Rome, by John Clare (1993). For kids, the whole political history from beginning to end.
Oxford First Ancient History, by Roy Burrell (reissued 1997). For kids. It skips around a lot, not trying to tell everything, just highlights.
The Romans: From Village to Empire, by Mary Boatwright, Daniel Gargola, and Richard Talbert (2004). Okay, it's a little dry, but it is up to date and has all the facts you could want.
The Roman Revolution, by Ronald Syme (1960). Still a classic.
the Gracchi to Nero: A History of Rome from 133 B.C. to A.D. 68
by H. H. Scullard (1959, 5th edition 1990). Another classic.