First of all - do not listen to those ppl who sayz that Talon sucks / is a sh*t / is a **** / etc. They are nothing, cause hes one of the best pubstompers and, of course, can carry the game on the low elo ranked as well.
What's the Talon, you can ask? Here we go.

My choice

Exhaust - pretty standart, especially if u are solotop. This spell works very good with every bruiser, and Talon is not an exception.
Ghost - I take it to combine this spell with our ulti. You can chase now at the speed of light and place your ulti correctly.

Good choice too

Ignite - Of course, you can take ignite, cause your Noxian Diplomacy makes people bleed for a dmg. But i don't like ignite for him.
Others are not so useful.

The Storyline
"Talon's earliest memories are the darkness of Noxus' underground passages and the reassuring steel of a blade. He remembers no family, warmth, or kindness. Instead, the clink of stolen gold and the security of a wall at his back are all the kinship he has ever craved. Kept alive only by his quick wits and deft thievery, Talon scraped out a living in the seedy underbelly of Noxus. His mastery of the blade quickly marked him as a threat, and Noxian guilds sent assassins to him with a demand: join their ranks or be killed. He left the bodies of his pursuers dumped in Noxus' moat as his response.

The assassination attempts grew increasingly dangerous until one assailant met Talon blade-for-blade in a match of strength. To his surprise, Talon was disarmed and facing down his executioner's sword when the assassin revealed himself to be General Du Couteau. The General offered Talon the choice between death at his hand, or life as an agent of the Noxian High Command. Talon chose life, on the condition that his service was to Du Couteau alone, for the only type of orders he could respect were from one he could not defeat. Talon remained in the shadows, carrying out secret missions on Du Couteau's orders that took him from the frigid lands of Freljord to the inner sanctums of Bandle City. When the general vanished, Talon considered reclaiming his freedom, but he had gained immense respect for Du Couteau after years in his service. He became obsessed with tracking down the general's whereabouts. Talon's suspicions led him to the doors of the Institute of War, where he joined the League of Legends in order to find those responsible for Du Couteau's disappearance.

''The three deadliest blademasters in all of Valoran are bound to the house of Du Couteau: my father, myself, and Talon. Challenge us, if you dare.'' - Katarina Du Couteau"

And that is the crystal truth.

I explain why i pick this runes for him. Of course, there are many options in this question.
Marks
Of course, its ArP runes.. No alternativez (extreme players can try +CritDmg, it makes him funny alot, but he needs then ArP items, you know). We want to stike hard as hell, and they will help us.
Seals
I've got dodge runes. You know, as for me - melee character can't be weak and "crystal". I think he must be a bruiser, a man who is ready to receive some dmg without a doubt. So, we can pick here Armor runes, or even HP/lvl as well, but he works pretty good with dodge.
Glyphs
I chose MRes runes because of reasons i told in the Seals article. He needs to be tanky abit, or he will be knocked out quickly. If u know u will be safe, you can take +atack speed runes or CdR runes.
Quints
Here is many options too. You can pick HP, you can pick Dodge too, but i just max ArP. Its good for me guyz, but feel free to experiment.

21/9/0 works well, he does not need mana regeneration alot, cause he has very lowcosted skillz. So, take dodge masteries and 21 in offensive. The result will be that u can take an amount dmg, and deal huge amount of dmg aswell.

I max Rake cause for me its more helpful ability early game. Its and AOE damaging and slowing spell, that can help u farm, to chase, to kill and to escape. It stacks with your passive - Mercy. So its more useful than others.
Q Noxian Diplomacy - is our second target. It makes good dmg output + placez a dot, that deals great damage too. Nice ability to stack it with Trinity Force.
E Cutthroat - I get this ability for a 1 point, cause we need it to chase and to place a silence. It gives uz +% of dmg against this target so, its cool too.
Our ulti is just awesome. If placed correctly, Shadow Assault can make a real dmg output. But its not the only way to use it. You can chase with it and u can escape of course. It has VERY low cooldown, so do not afraid to use it.
So the priority is - R > W > Q > E

If u are 1v1 on top - be agressive, but do not overextend. Talon has very good animation to lasthit, and good abilities to make our life easier on lane. Farm with Rake and Noxian Diplomacy, but do not push!
I get Cutthroat early, cause maybe your jungler wants to assisst you even in the beginning of the game and u need a spell to chase an opponent and place a hit. Our key to success is good laning. Do not forget to buy wards - your life will be much easier with em. Go only for a safe kill and do not dive a tower too long.
And of course - its better to go back and heal, than die. Remember this.
Escape gangs with ur Shadow Assault.

If u go solo - feel free to take Doran's Shield. If u r duo with support - go for Doran's Sword. I've wrote the itemization above, so here i will explain some options.
You can go tanky aswell, i mean make Warmog's Armor and Atma's Impaler - but its for extreme playerz. If you just feel you are too weak to receive the damage with my itemization - go more tanky, but do not forget - you are not a cleat tank. Play your way.

You are bruiser - just do your job!
AP carryz - your targets guyz. Place a silence, make your AOE strike most of ur enemies.
Press Q after a hit, cause it resets the cooldown of your autoatack. Don't be scared to take some damage. And of course, place ur ulti to make your enemies cry. Chase them, assassin, chase them!

Pros:
- has huge damage output (AOE dmg aswell)
- can receive an amount of damage and survive
- good escape mechanics
- usefull in battle (silence+slow to help ur friends to kite an enemy)
- funny
Cons:
- expensive itemization
- not so strong early game
- can be countered with oracle's

To sum up:
Talon is your ticket to rule some normalz and low elo rankeds. Just play smart, cause this hero has very good potential and can turn the tablez sometimes. And the main reason to play Talon - he is very funny character. He will give u so much fun!
But do not forget - The player makes the game, not a champion.
P.S. Its my first guide so - feel free to comment, vote and make me cry :)