Once popular Victorian writers like Wilkie Collins and Anthony Trollope have been mostly forgotten by modern readers. Charles Dickens has remained uniquely popular for years for a reason: His stories resonate across the century and a half that has passed since he did most of his best work. If you haven't read Great Expectations, A Tale of Two Cities, and David Copperfield, I recommend that you do so now.
Then you should read Claire Tomalin's fine biography of Charles Dickens.
Charles Dickens was a brilliant artist, but a complex man. He could be alternately warm to his acquaintances and cold to longtime friends and close family members. He never got over his childhood experiences of poverty.
By the standards of his time, Dickens had an expansive social conscience. But here again, there were contradictions. Dickens actively supported the rescue of "fallen women" (prostitution was rampant in the London of Dickens' era). However, he left his wife in late middle age to pursue an affair with a woman young enough to be his daughter.
Dickens would be interesting in the hands of any reasonably skilled biographer, but he is especially so in the hands of Claire Tomalin. Biographies of historical figures are sometimes skewed to one narrow aspect of the subject's life. Tomalin achieves a balance that makes Charles Dickens compelling to read: Here we have an in-depth study of a writer, a very human man, and an era. (Tomalin has done her research on 19th century England, and you'll learn a lot of historical facts as well.)
This is an excellent biography of Charles Dickens. Enjoy.