In writing--and even real life--there are truly only four different character types. (This is true for heroes anyway, villains are a different matter and I will probably get into that later) These four character types are seen in books and movies all the time whenever you have a group of characters. You will also probably be able to cast your own friends in these rolls. I know I can ;) I'm going to be using a popular example that I hope everyone will know. The Three Musketeers and D'Artagnan. They characterize the four character types perfectly so they will be a good example. If you have not read the book, then just listen to what I'm saying ;)
First of all we have D'Artagnan. He's the hero of the story, the main character and that which most of the story revolves. Heroes can take on any of these character types I write about today, but the usual popular traits given to your protagonist are like D'Artagnan. He's young, to start with. (Again, this may not describe your hero, but bear with me, this is only an example!) He's rash, and a bit arrogant as most young men are. He's not yet worldly wise, and he gets himself into trouble because he's too quick to act before thinking. This is a good way to start your hero out. Make them a bit stupid maybe. Characters, especially main characters sometimes need to experience growth where they learn by the end of the book not to run around slap-dash and get yourself challenged to three duels in one day. Now, D'Artagnan was rash and foolish, but he was also brave, and noble and he was loyal to his friends and would really do anything for them.
Next we have Athos. He's the unproclaimed leader of the four friends as he's one of those natural leaders who anyone will trust in a bad situation and will go to first when asking advice. He's quiet, he's melancholy, and he has a dark past that haunts him to make him so. Athos' character is another popular one to choose for your hero/protagonist if you're a fan of dark brooding heroes (which I am ;). He also is very loyal, seemingly unflappable though certain things might push him over the edge. Sardonic, though not without feelings for his good friends. Athos was almost a father figure for D'Artagnan in the books though he was not really old enough to be thought upon as one. But there were many times he treated the young Gascon as a son or younger brother with advice and help when he needed it. If your main character is like D'Artagnan, you'll probably need an Athos to keep him in line and help him on his way.
Third, we have Aramis. Aramis is the scholar, he was training to be a priest before he got into a duel with someone and decided it was better for him to become a musketeer. He's somewhat undecided with his life, he fluctuates his feelings, but yet he is always wise and is the one who keeps the friends together, getting between arguments and such, though not above causing his own. He keeps many secrets, though none dangerous and is one of those somewhat transparent people that you can always see through and tell when he's lying. He may not tell his friends the truth, but they all know anyway. Characters like Aramis are the "quiet ones" the ones who always know what you need them to when someone needs information. Again, a type of character that is important to a book.
And lastly we have Porthos. Porthos is the rock of the group. He has no dark past to haunt him, he has no secrets and qualms, he's a man who lives life as it comes. He acts on the spur-of-the-moment and yet does not seem as rash as D'Artagnan. He tells the jokes, he's the comic relief, and because of that is a very endearing character. He might seem lackadaisical in a normal situation, but he will always come around when needed and there's danger to be taken care of. Every group of friends, needs a Porthos.
Anyway, that was my little character type analogy with the Three Musketeers and D'Artagnan. It's not definitive by any means, but these are truly the four most popular character types you see. I hope to write a companion to this post about villains. They are completely different creatures all together!
By the way, if there is ever any particular aspect of writing you wish me to address, please let me know! I'm here to help you inspiring writers or even seasoned ones who need a new idea. Don't hesitate to ask!
And also write in to Samuel Pepys for holiday help! You know what to do!