However, where writers (myself included!) run into trouble is when we want to tell the main character's entire backstory in the first chapter or two.
Don't get me wrong...I'm sure that your main character has a life story that would put Nobel Peace Prize winners and soldiers of fortune to equal portions of shame, but the reader doesn't want to hear every detail of it all at once.
Think of books you have read, where the story doesn't seem to get moving until the third or fourth chapter. If you go back and read those--that is, if you still own those books--you will probably find that the author spent those first two to three chapters helping the reader get to know the main character.
This sends one of two messages to a reader:
1. The author doesn't trust that the audience can handle having backstory and plot happen simultaneously.
2. The author feels a need to justify his or her main character's importance before any plot can ensue.
The first message will leave your reader insulted, and probably cause them to leave the book on the store bookshelf or in the online shopping cart, unpurchased and unread.
The second message indicates that the character is stronger than the plot. To some degree, you need a character who is strong enough to withstand the plot...but if you make the main character too impressive, then the plot will look laughably simple by the time if finally happens.
My recommendation? Start with a bang, not an explanation. As an example, I wrote the first 250 words of a novel. I haven't ironed out the plot points yet, or given my main character's entire life story. Here is the start of that novel:
Tserenia pounded on the chamber door frantically, hopeful that her urgent knocking would create enough noise to waken Zanral, but not alert her pursuers—her own family—to her presence.
“By the elements, Zan, if you do not let me in, I will splinter this door and use you as a pincushion!”
The door inched open a crack, and Tserenia saw Zanral’s face—strong, square jaw, but tired eyes. Very little of his weariness was due to the late hour, Tserenia knew. Zanral’s status in this castle was something they had commiserated over, and the reason that Zanral would either gladly help her escape or eagerly turn her in.
“You are as polite and genteel as ever,” Zanral remarked dryly, and then yawned.
“My bearing is not the issue,” Tserenia whispered as she glanced down the hall, either hearing or imagining footsteps closing in. “My magic is the problem.”
“Are you saying that splintering this door is beyond your abilities?” Zanral asked jokingly. “It was an impressive claim. I must remember that tactic.”
Briefly, Tserenia wondered whether Zanral meant using his own elemental magic to break doors, or the art of bluffing. Rather than waste time clarifying, though, Tserenia explained, “No, my other ability. Zanral, they know about my unnatural studies, and I am in danger.”Tserenia took a deep breath, the words still strange to her, even as she admitted, “My family discovered that I am a necromancer, and now they are trying to capture me. Hide me, please!”
While I would have loved to explain exactly how Tserenia knows necromancy, what her relationship with Zanral is, given an anecdote about the people who are chasing her, and explained just what type of spell has kept them from catching her...all of that can wait until later.
The important thing to do with a beginning is this: begin!
I know it sounds simple, but getting a story off to a running start is a real challenge. Remember to start with some sort of action. A fight, a debate, a conflict...anything will do, whether it's a martial arts contest to a character agonizing internally over what to wear the first day of work. Just make sure to grab the reader's interest as soon as possible.