For my Summoner Spells I use Ignite and Ghost, this is purely for spike damage against opponents and to chase/run away. In laning and team fights most people don't expect a Shen to be able combo hard with Ignite, Vorpal Blade and his passive so it makes for a very good killing tool. Depending on the enemy team I sometimes take exaust also.

Note: If your going to go jungle Shen all you need to do is change the Ignite for Smite and get the 1 point into longer buffs.

My runes are pretty basic which consist of movement speed, health, magic resistance and attack speed. Since I get Wits End most games and sometimes other attack speed items the attack speed in my runes really helps with them, also its important for your farming.

I do the typical 0/21/9 for tank masteries, nothing special.

For my items I have got 5 so far, the 6th one is very different everygame, I will either get:
Spirit Visage
Guardion Angel
Aegis of the Legion
Atma's Impaler
Madred's Bloodrazor
Or
Thornmail
With all my items + one of these and a red potion you will have around 3200-3500+ HP which is normally enough, anymore and your sacrificing to much armor or magic resistance for health. Since your a tank you have a natural high amount of survivability so thats why I get Wits End, and that it helps with magic resistance. Now you can not only tank for team fights, but Wits End helps your to farm minions, to disable other tanks and DPS who have low max amounts of mana and do decent damage overall in team fights. If the game drags out to where everyone has full build and you get Madreds + a green potion you will have around 2.0 attack speed and have a very good chance to beat lots of other champions 1 on 1. I will only get Aegis if no one else on the team will get it, and for the others it heavly depends on who your facing.

I normally start with Vorpal Blade unless we are going for a level 1 team fight or to gank a enemy jungler, in that case I will get my dash.

Early Game:
At level 1 you want to head over to bottem lane unless your the jungler, use your passive and vorpal to last hit minions to farm, don't bother to harass just yet because your Vorpal does next to no damage. At level 3 you should get a feel for your opponents on if they are playing aggressive, or defensive farming. Depending on who your laning with and if they have a healer I would try to Vorpal them once a while. At around level 4 your going to want to watch for your jungler and your enemy jungler to set up ganks. By level 6 your going to want to have around 1350+ gold so you can buy your boots/heart of gold and possibly some wards, then be able to either ult back into your lane or gank another.

Mid Game:
After level 6 people tend to not stay in their lanes anymore so you want to ALWAYS keep the corner of your eye on your mini map, make sure you notice when either a champion is diving, getting tower dived, or ganked by an enemy, this is VERY important. Also remember that its more important to prevent the enemy from farming minions and getting exp than killing him. If the enemy gets low life and you think you have enough damage to kill him but your not sure, DON'T go for the 50% kill and the 100% death, its always more important to not die rather then to kill a champion.

End Game and Team Fights:
By now your going to hopefully have the 5 main items and be working on your 6th, during team fights your going to want and taunt as many people as you can at the start and pop your Omens, lay your Vorpal, Ignite, and passive first hit on the enemy carry then head back and protect your own carry. Keep an eye out for the first person on your team whos being targeted and try to use your ult on them, if your the one being targeted thats even better, just plow through the team to their squishies and start killing them, if you get low and you know the rest of your team can ace them, then try to retreat, go heal and ult back in. It is always worth it for you to die first as long as your team can finish them off with little or no deaths.

Anyways this build helped me get 1750+ ELO, this is my 2nd guide ever so please rate and comment, if it gets popular or if I get any questions I will update it.