This is my first guide so please excuse any errors or things that need to be clarified. I'm a master tier with over 700 Shaco games (Season 4). He is my most played champion and I enjoy his high-risk high-reward playstyle.

Runes are standard and there are other variations but I personally think mobility quints and flat AD marks are essential because these heavily affect the pathways you are able to take during ganks.

21 points in offense is a must. You can decide on whether you need defensive stats or utility but I believe utility is better.

Wriggles over Spirit Elder:
I personally prefer wriggles over spirit elder because it allows you to clear camps quickly and also helps you through mid-game if stacked properly (also extra gold).
Spirit Elder is probably only better for its sustain and I would only opt for the spirit stone if i wanted the extra sustain to farm the jungle.

Depending on your jungle path i'd take (Q) Decieve 2nd if im going for a level 2 gank or I find the enemy jungle could pose an early risk at the second buff (Lee Sin).
Otherwise (E) Two-Shiv is better because it provides slightly faster clear times with an extra miss chance on monsters which could save you a pot or two.

Pros:
Strong early ganks
Invade power
Flash every 10 seconds! (Q)
Solo Dragon @ 6

Cons:
Squishy
Weak CC for team fights
Pink wards / Oracles