Okay here's some rough ideas.
Episode I
CHARACTERS:
The Lars family:
Anakin Skywalker lives on the moisture farm with his stepbrother Owen, Owen's girlfriend Beru, His stepfather, and his mother. His father abandoned his mother when he was very young. His other family members have the name Lars (His stepfather's name) while Anakin has the family name Skywalker, his mother's maiden name. Anakin's mother is in her late 30's or so and could be similar to her portrayal in Episode I by Pernilla August. Anakin's stepfather is older, say in his 50's, is very ill and cannot work on the farm.
Anakin and Owen:
The two boys do all the farm work and their parents rely on them to make their living. Anakin is about 15 or 16 and Owen is about 19 or 20. Owen is courting Beru and expects to marry her soon. He has a very practical work oriented mind and only thinks of providing for his family and his girl. When Obi-Wan comes to whisk Anakin away he is very upset at Anakin and argues that he needs to stay to provide for the family. He sees Anakin as an idealistic person who doesn't put family first. Anakin, like Luke, is very adept with computers, technology and piloting. He has a strong imagination and always looks toward the future. He parallels Luke in many ways although he also has a harsh, resentful and impulsive side to his character which isn't present in Luke. He is always searching for bigger and better things. He has a very close attachment to his mother but doesn't have good relationships with his step family. His mother and the Lars family were only married together a few years ago. When Obi-wan finds Anakin he immediately senses his capacity in the force and thinks Anakin is so unusually adept that Jedi code regarding age and history (The Jedi like to start with clean slates) should be broken to allow for his immediate training.
Obi-wan Kenobi:
Obi-Wan Kenobi is a young Jedi knight in his prime. He is in his late twenties or early thirties during episode I. He was a prominent pupil of powerful Jedi master Yoda and was selected for an important mission. When he finds himself on Tatooine and stays in the Skywalker home he is not liked by Owen, who sees him as an idealistic philosopher who lives a life of grandeur, knows nothing of real work, and is mooching off the family. Anakin is fascinated by his stories of the Jedi order and wants to be taken to Coruscant trained. His mother also takes a liking to Obi-Wan and believes life as a Jedi may be the best think for Anakin, who is always looking for bigger and better things and does not fit in well with the Lars family. Obi-Wan does end up taking Anakin to be trained.
C3PO
This droid is unnamed at this point. He was obtained by Anakin from a junk pile and Anakin fixed him up. He has unfinished rusty body plating. C3PO isn't assigned his number name yet and when Obi-Wan asks about the droid the Lars's say he has no name. C3PO can speak no languages other than Galactic Basic and a few other odds and ends and is generally is of no use to the Lars family. "He can't even speak Bocce" and is the most complex and at the same time to most useless droid in the Lars household. He constantly whines and nags and is a general annoyance. Obi-Wan agrees to take the droid with him as well as Anakin. Later in Episode I he is assigned a number and given his gold finish, his memory is also wiped. What the Lars's didn't know is the C3PO has an incredible capacity for learning. He can pick up information very quickly and easily (all protocol droids can) and by Episode IV he is "fluent in over 6 million forms of communication" Obi-Wan sees his use where the Lars family cannot. 3PO, with his different finish, new number, and many new abilities, is unrecognizable to Owen in Episode IV.
R2D2
R2D2 is a personal Astromech and utility droid owned by the Jedi order. (The Jedi have no worldly attachments, everything they own is owned by the order and free to be shared between Jedi). He is currently in the possession of Jedi knight Obi-Wan Kenobi. Kenobi uses R2D2 to help pilot and repair his ship (most Jedi aren't terribly technologically adept) as well as to transmit and receive messages and other utilities. When on Tatooine, R2 quickly befriends C3PO.
MORE COMING SOON...