Djeta Thernadier said:
Wasn't there an awesome list in a thread a few months ago? I tried searching for it but I couldn't find it. It was a list of questions for the individual characters background, as well as how that character came to meet up with the others.
I remember that thread!

I started that thread when I was compiling my own list to distribute to my players. Here was the final product. I've edited out some of it (because they were references to my own campaign world, which I doubt would be helpful examples for your players). Hope that it helps. Here it is:
FATHEAD'S GUIDE TO PERSONALITY
I put this together to help players develop interesting and unique characters during play. A player who really enjoys playing their character is almost always enthusiastic during play and has more fun at the game table. It's important that the character's personality is prepared before the first session in which it is used, and more importantly, its traits must be made clear in that first session.
Above all else, I’d like your character to be someone that you are interested in and want to see develop.
PHYSICAL APPEARANCE
There are many ways that a character can be defined. Physical appearance is the first, although seldom is it the most prominent. Think of how YOU dress. How you dress and look is indicative of your personality.
PHYSICAL APPEARANCE QUESTIONS
1. How does the character wear his or her hair? If male, how does the character wear his beard?
2. Does the character have a distinctive style of dress?
3. Does the character have any distinguishing marks? Tattoos? Scars? Where and how did the character get them?
If you have a scar or tattoo, ask yourself where your character received those. Was the scar from the six-fingered man, on whom you’ve sworn revenge? Did you receive the tattoo in the shady “Nighting Ward” when you joined a small band of thieves?
PERSONALITY QUIRKS
Have each PC give at least 3 personality quirks. Something like: loves seafood, never sleeps in a room with a north window, and obsessively cleans under his fingernails with a dagger
AMBITION QUESTIONS:
1. What are the PCs ambitions?
2. Why do you adventure?
This section is one of the more important defining characteristics – what is your character’s driving force? What do you want to do? Why did you become an adventurer?
Perhaps you are a mage that searches out creatures for interesting spell components. Maybe you are a druid that wishes to find unusual woodland creatures to both preserve their species and provide protection for their future druidic grove. If you are a fighter class, perhaps you wish to raise an army to take back his family’s homestead that was usurped by a local baron, or simply wish to purchase land and title for your impoverished family. If you are a thief class, perhaps you horde gold so that he will never have to scrounge for food in alleyways or steal to eat, ever again…
Maybe you just adventure for the excitement and the chance to visit exotic lands – the sort that bards tell tales about or despise the mundane laborers, and instead desire the glorious (and often tragically short) life of an adventurer.
In the end, your character’s ambition is up to you, but make it something that would be interesting.
PERSONAL LIKES/DISLIKES QUESTIONS
1. What are the PCs personal likes/dislikes?
2. What are the PCs attitudes towards other races?
3. Do you have any superstitions?
4. What is the character’s favorite food? Least favorite food?
5. What is the character afraid of? Is there a reason for this fear?
Do you have a particular liking for drinking elvish red wine that has been aged for a 100 years? Perhaps you even enjoy collecting particular vintages of wine, and aspire to have your own wine cellar or vineyard.
CHARACTER HISTORY QUESTIONS
1. Where is the PCs family, who are they, what to they do?
2. Who are the major figures in the PCs life that shaped his desire to adventure?
3. Is the PC religious? If so, what deity does he revere?
4. Does the character have any siblings? Where are they? What do they do? Are they married?
5. What has the character done in the last five years?
6. Was the character born in a rural or urban environment? Where did the character grow up?
7. What was the most important event in the character’s life? Why?
8. Who is the most important person in the character’s life? Why?
9. How did your character survive/earn a living BEFORE becoming an adventurer?
10. Does the PC have any known enemies or competitors?
Where you came from helps to define the person that you are.
If you were born to a noble family, perhaps you have haughty notions of other social classes. If you were born to a low class, you probably had many times when your family went without food or proper warm clothing.
YOUR EQUIPMENT
Your ideas on providing background for your items is a great idea. Maybe the fighter's cloak (with blood stains on it) is a hand-me-down from his deceased father. Even if the history is mundane, it can be interesting:
"as a child, my character was given a colorful strip of cloth from a travelling gypsy during the festival for the Season of the Winter Usher, which she now wears in her hair"
Perhaps the stories of the world that the gypsy woman told were part of the reason why this character adventures.
A player of mine had a character, Shaldatha, who owned a horse named Fabersholl. Fabersholl was the oldest, slowest, and most cantankerous horse that anyone could own…but Shaldatha loved that horse, and refused to go anywhere without his companion (even if the old mage could NEVER pronounce the horse’s name correctly). Shaldatha would actually cast protection magics (such as stoneskin) on his horse. The horse itself had a personality and because of that, it made it more interesting.
So, be sure to give the same attention to 2 items. Your character starts the game with several items, it would be nice for some of your equipment to have meaning for you. It’s less interesting to say:
“I have a longsword”
as opposed to
“I refuse to part with this longsword, because it was my great uncle’s – who was also an adventurer and a great swordsman”