James Pleiades Hawkins was born to Leland and Sarah Hawkins while they were still very young. Leland was a spacer/miner, and we can only assume that Sarah held the same kind of job she does in the movie.
Jim was a very bright boy, showing aptitude for sailing at an early age. When he was eight years old, he built his first solar-surfer, a hobby he practiced ever since. As a very young boy, he loved the story of Captain Nathanial Flint, and his secret stash hidden somewhere on the legendary Treasure Planet.
When Jim was nine years old, his father left them, without even saying goodbye. The event left Jim heartbroken, as earning his father's approval was the one thing he strove to do. He began to grow bitter, and even slightly resented himself. His confidense was all but lost; his grades started dropping, and he became more withdrawn.
Finally, one day when he was fifteen, the chance of a lifetime literally crashed in his front yard. An old pirate named Billy Bones gave him an odd sphere just before he died. Upon further examination, Jim discovered it was the map the long-lost Treasure Planet.
With a little help from Dr. Doppler, Sarah agreed to let Jim go on the adventure to find the legendary loot of a thousand world. But it wasn't all fun for Jim. On board, he was assigned the the lowly position of Cabin Boy, under the ship's cook, John Silver.
Silver and Jim didn't get along very well at first. Silver made Jim work hard. But after a while, a deep friendship was forged. Silver began to be the father-figure Jim needed in his life. Under his guidance, he began to learn how to channel his talents into more productive measures.
Unfortunely, Silver was also planning mutiny as well. We he and his crew of pirates took over the ship, Jim bravely stood up to him, and standing by the captain and Dr. Doppler. But even so, Silver had taken a liking to Jim, and ended up saving his life in the end.
On the return home, Silver escaped, rather than facing a life in jail. Once more, someone was leaving Jim's life, but this time he had learned that he had it in him to be great anyways. After the trip to Treasure Planet was over, Captain Amelia wrote a letter of recommendation to the Interstellor Academy, saying "They could use a man like you." Jim now faced a bright future ahead of him.
As you probably know, Treasure Planet is based off the original classic novel Treasure Island, by Robert Louis Stevenson. So I guess it goes without saying that Jim is based off the original Jim Hawkins in this same book.
Since I have not read the entire book yet, I can't tell you much more. When I'm finished, this part will definitely be put it.