The story is seen through scouts view...scout represents Harper Lee and her opinions etc
Jem is scouts older brother and she looks up to him a lot... as he gets older you can see the transformation he takes. At around the age of 12, he becomes more aware of whats happening around him and shows his maturity.
Atticus is a lawyer and was chosen to defend Tom Robinson. You can see that he doesnt want the case to effect his children and that he is a gentleman to everybody (including blacks).
Its not a sin to kill a Blue-jay, but its a sin to kill a mockingbird: The mockingbirds represent the black community and Atticus believes that its a sin to kill them as they have done no wrong, just like mockingbirds cause no harm.
Aunt Alexandra wants the children to know about their background and is very particular when it comes to Scout acting like a lady. You see a different side to her at the meeting when Mrs merriweather is being hypocritical and talking about Atticus.
Boo Radley is a mysterious person who lives at the Radley place. Apparently he stabbed his father in the leg with a pair of scissors.
Mr Dolphus Raymond is a man who is seen as a drunk. Actually he pretends to be drunk so that he has an excuse for wanting to be with a black women.
Dill is Scouts 'Fiance' and ran away to live with the Finch's. He's usually passed around from family member to family member but you can see that he respects Atticus and see's him as a father figure.
You can't understand someone untill you have jumped into their skin. Scout learns this from Atticus when she's complaining about her teacher Caroline Fisher.
Mayella Ewell accuses Tom of ****** her but Tom says that she Kisses him. I believe she accused him so that she wasn't seen as a disgrace for kissing a black man.
Mr Ewell seems like a bad father who is a drunk. It is hinted in the book that he beats and takes advantage of Mayella.
Tom Robinson has a bad left arm as he got it caught in a cotton Gin when he was younger.