Resources and house rules, and so on.
Note that the nine attributes fit in a grid: each category (mental, physical, social) has a power attribute (Intelligence, Strength, Presence), a finesse attribute (Wits, Dexterity, Manipulation) and a resistance attribute (Resolve, Stamina, Composure).
A given task will couple the most appropriate attribute with the most likely skill. Some actions are described in the rules, while others the referee will determine on the spot (and sometimes things written in the book might get made up instead anyway). So a mental task requiring sheer power of intellect would require Intelligence, one requiring mental agility might be Wits and a mentally exhausting task could be Resolve.
For social tasks, Presence is about getting your way by force of charisma and inspiration, Manipulation is for subtle trickery and Composure is for keeping your cool. There's a fine line between Resolve and Composure, but most tasks can be distinguished as mental or social.
The physical attributes need little explanation; they're pretty much the same in every other game...
Sometimes a task is borderline and I'll let you choose. Sometimes I'll let you roll what you want if you've got a good justification for solving the problem with those traits. Sometimes I'll be considering things on a case-by-case basis and I don't promise to follow precedents consistently.
Some attributes contribute to other mechanics. The resistance attributes are often used as a penalty when opponents use that kind of action against you. Stamina helps determine health, while Willpower is Resolve plus Composure. Defence is the worse of Wits and Dexterity.
Once the task has a skill and an attribute, you add together the dots, roll that many d10 and count those that are 7 or better (although I might have a house rule letting me specify other target numbers where appropriate). This means that skill dots are as powerful as attribute dots, albeit more specialised. Skill specialities are further refinements in which you specify one favoured facet of a given skill: when it's relevant it's worth a bonus dot. You can have as many specialities on a skill as you like, but you can only claim one at a time.
When you have no dots in a skill, you suffer a penalty that depends on the category: -3 dice for mental, -1 otherwise. This means that the first dot is the most valuable, since it's a increase of 2 dots or 4.
Two is a respectable skill level, especially at your age. Three is the [normal] maximum for child characters, and is really quite impressive.
Computer: You can just about use one without dots, but not to get anything interesting done. Crafts: Making/fixing stuff with your hands. Investigation: Search, analyse scenes, interview people, etc. Medicine: At the levels we're talking, you could be pretty good at first aid. Occult: Know lots of folk tales and legends, maybe something more sinister. They may or may not be true. Politics: Both political theory and current affairs, as they apply to real politics or even playground politics.
Study: Academic and other book knowledge. Adults have parallel skills: Academics and Science.
Athletics: Running, jumping, climbing, throwing... Brawl: Unarmed combat. Firearms: You better have a damn good reason for taking this. Larceny: Picking locks, pockets and other sleights. Stealth: Hiding and moving undetected. Survival: Finding food, water, shelter and so on in natural settings. Weaponry: Armed close combat.
Animal Ken: Getting on with animals, understanding them, training etc. Empathy: Judging motives, lies and so on. Expression: Writing, composing and on small scales speaking well. Intimidation: Subtle or otherwise. Persuasion: Convincing people of things (especially when you believe it). Socialise: Having fun in company and making sure everyone else does. Streetwise: Knowing how to find things and get by, on the dark side. Subterfuge: Making people believe things when you don't...
Every child character has a dominant positive trait and a dominant negative one. They needn't be balanced and they won't be the character's only trait, but one of each is specified. When short term actions fit the character's Fault he regains a Willpower point; when longer term action is in keeping with his Asset his Willpower is refilled. I'll run through a list of sample Assets and Faults when we meet up.
When you absolutely have to get something done you can spend a temporary Willpower point for a three-dice bonus to one roll, or a two-dot bonus to a resistance attribute to resist one enemy action.
I'm not going to explain combat until we need to know it, so that's more or less all you need to know.
By request, a quick run down on the traits and stuff is here.
The fifth dot in most things costs double, but I don't expect you to be able to afford any fifth dots.
You start with a free point in each (already inked in). Pick your favourite category (Mental, Physical, Social) and distribute 5 dots. Pick your next category and distribute 4 dots, then 3 in the final category. For a balanced character it pays to have two dots in each attribute (which leaves you with little choice of how to do that tertiary category...). Attributes are capped at 5; remember the last dot is double.
No free dots this time, but otherwise much the same deal: 7 dots in your primary category, 4 dots in the secondary and 2 in the tertiary. Finally pick one skill and specify one aspect of it in which you're specialised. Skills are capped at 3 for most children; see the Prodigy merits, below.
Distribute 7 points across the following list (costs in brackets; the fifth dot costs double):
You should be able to find everything else you need somewhere on the character sheet.