There's his Q:
Basically a dmg buff (AP scaling.) which if goes through the enemies slows them, and gives + dmg. Lasts for 3 Hits.
The W:
You always max this last but if you don't use it in the right moment... everything is ****ed. It's basically an aa block for 1.25 seconds.
The E:
A taunt which lasts for just enough time for your team to get a great engage.
The R:
You might think Shen's a jungler by this ability. Basically you can tp to any of your teammates with a little delay. It gives a sheild but if the person you are trying to tp to dies. You'll stay but still get the cd.

If your E is up you should always look for poke, clear the wave and make sure your taunt hits the enemy. If it does activate your Q and try to bring it through the enemy.
You should activate your W while he's taunted or right after the taunt went off.
With the help of the minions you can easily secure the kill.

Pros:
Has decent damage and tanky.
Great skins :3
Has energy
I could say all the juice stuff but i don't have time.
Cons:
He lacks mobility (not counting ult)
Farming is a bit hard without your Q
High cds

Teamwork when playing Shen is the key to victory.
If you use your e well, thats free kills.
Your w can save anyone from your team.
Your ult is basically an insta shield/tp.

As I wrote earlier {Pros / Cons} farming with this this champ is pretty well decent. If you have your q up. Which you always have... Since it has a low cd. Than you should use it.
After Titanic Hydra is finished your job will be easier.

I know this has nothing to do with the guide but I wanted to mention that the skins for this champ are pretty gr8. I use the Surgeon, but will use the Pulse Fire Shen when it comes out.

Thanks for reading this short guide on Shen, I hope that I could help you with anything :3
Gl Hf.