this is my first guide
thing i wand to change in the near future:
1: pictures
2: more detailed info over her skil usage, ganks/harras, items, runes
3: a clip on how to play her
4: inprove build or make several viable ones
5: let people learn to enjoy playing her

Pros:
great poker/harasser
ranged
cc
can protect your selves and other
good escape mechanisme
scouting ability

Cons:
squishy
her range is limited to her pet leasing
not so great early game when it comes to farming
early game mana starvation if you;re not careful
all her skil work on het pet

Makrs
i choose Mpen runes cause you're skil based and you deal magic damage, so Mpen will increase you're damage.

Seals:
for the seal i took lvl scaling mana per 5 sec. the reason fot this is you will get mana starved if you don't get blue th counter this a bit i took these runes. if you're more comfortable with direct mana per 5sec those are great also.

Glyphs:
for Glyphs i take direct ap cause you'll need ap early game. other Glyphs that work fine are Ap per lv and CDR runes.

Quintessnese:
i take direct ap for the sake of a stronger early game, but there are many Quintessnese that you can like : hp (for langer laning) or ap per lv( if you prefer then)

for the masteries its pretty straight forward 9-0-21 cause you will need mana regen, some CDR and archaic knowlege is just an nice damage boost. and these mastery will provide what you need

for the skil sequince i max q first cause this will be you;re main damage early/mid and i lv w with it a bit so you can harras/poke better. i have put 1 lv in e on lv 4 so that you can help other and kill creeps easier.

IMPORTAND NOTE: you are very squichy.
always know were you're ball is(this is hard sometines in team fights)
you can carry, but helping teammates to not die is inportant also
you're Q skil can be used to scout

Early game:
if you want to harraras use the Q+W combi. if you want to farm creeps use Q to hit every creep and land on the wizards(once lv 4 or higer) use you're E to get the ball back to you and damage the surviving creeps. but do not play to aggressive with orianna unless you really faceroll then cause you're really squishy until you get RoA.

Mid game:
if things are going good you can try to gank but you're still squishy even with RoA, so it's not really advised to do so alone. to farm creeps just do the same as early game. but you have you're ulti now use it wisely in team gank to stop then from running or even iniatie(not advised) or just to finish of the other team. a combi that smart to use in ganks/teamfight Q+W+E+Q(+R)+W

Late game :
try to finish the build as soon as possible and help in team fight with the combi Q+W+E(on someone close to enemy or the one who needs) and then Q+R+W and they should be dead if you're team is good

for items i start with an doran ring for the extra hp ap and mana regen, but if you don;t like get an Saphire crystal + hp pot so that you will get RoA earlier. after you have RoA get Soc boots and you're rabadon for an good Ap boost if you're still getting mana starvation you can get morello's evil tome first, when you have Deathcap and Morello's build for Rylai's fot more ap and extra CC and more ap of course. after that i would build for a Will of the Ancients for it gives spell vamp and more ap. when you have bought all you;re items get the 4pods so you will get an nice shining aura.

extra info: if you feel you're damage is low it's never bad to buy an Exiler of brillance.
if they can gank to easy get some wards.

Situation items:
Zhonya's hourglas: this item gives an nice ap boost and an live saving passive
Abysal Scepter: for some mr if you need along side with some ap and lower mr on enemy's
Void staf: take this if there stacking Mr
mejai's soulstealer: if you're team is facerolling then this is a good choose but be aware they will focus you even more if you;re not carefull
Archangel Staff: if you want a very big mana pool along side more ap, build for a tear of the Goddess early if you know you want this
lichbane: if you wand to auto attack this is an item for you but beware you'll come close to the enemy
if they kill you to easy it never hurts to get some defensive items

for the summer spel i will take flash and ignite

flash: great escape especially with W

ignite: just to finish off for some early kills or to stop hp regen


clarity: is a great sum spel but not really needed with regen runes and evil tome

ghost:a good sum spel but i prefer flash

clairvoyance: a good sum spel if you wanna know were you're enemy's is

Teleport: a very goos sum spel if a tower can be saved be it or you just want to get back to you;re tower fast after you bought something or died