To Round Out The Guide...
Those who have followed this guide know that this was originally just a guide to JUNGLE Shen. However I feel that now it is time to begin making this guide something better, something that every kind of player can take something from. A more detailed section will come later but for now here's my stance on lane Shen.

For Those New To Shen (Basics)
[MOUSE OVER THE ICONS FOR ABILITY DETAILS, THE DESCRIPTIONS PERTAIN TO THE RECENT BUFFS ONLY]
Shen is a very useful champion, but that's probably not why you're trying him out. You are almost certainly using him for your first time because he is a ninja. And that's cool, but before you go off doing your ninjutsu business you should probably know how best to use said ninjutsu to help your team. I'll begin by breaking down his abilities.
Ki Strike (Innate)- This passive has been remade to reduce its cooldown when you attack, instead of when you are attacked. This change gives Shen the extra strength needed to compete with other top-tier jungle champs.
Vorpal Blade (Q)- The heal now scales off of your maximum health, a fantastic change considering all the health you'll be buying throughout the game. Oh and for those who lane with Shen, last hitting with this grants a portion of your heal now =D
Feint (W)- This is actually useful now; the scaling has improved dramatically and it's added interaction with Ki-Strike makes it a very important skill now.
Shadow Dash (E)- The utility of this skill has skyrocketed. The taunt duration no longer scales, but now it starts at 1.5 seconds so you have no NEED to level this early. It now does AoE damage, so you MIGHT want to level this early. It reduces incoming physical damage by 50% at all levels, a much needed addition considering the role that Shen is supposed to play
Stand United (R)- Your teammates will love you forever if you know how to time this, because it can turn the tide at the press of a button. You can save a fleeing carry, your pusher can tower dive without fear, the possibilities are endless. This ability became even greater in the new patch with a 1.5 AP ratio and 0 Energy cost, so you can 100% of the time have your skills usable afterwards.
Shen is simple, and that's why he's so great. Keep your team alive and you're doing your job (don't be worried if your death count is high, as long as your allies death counts are low). But be sure to manage your Energy levels, because your max energy does not increase per level, and neither does the rate of regeneration (except with blue buff). Space out the timing on your skills as much as you can afford, to reduce the risk of being unable to use them.
Masteries and Runes
9/21/0 is the optimal set-up for solo top Shen.
The buff to
Ghost and
Exhaust as well as the extra AP, CDR, and magic pen. help Shen greatly in lane.
Defense tree is just OP to begin with, and since Shen scales well from health it is that much more important to invest in this tree.
You can run whatever you want on Shen and you'll still destroy everybody, however these are the runes I prefer on Shen in lane.
Greater Mark of Magic Penetration x9 to improve your Q spam.
Greater Seal of Armor x9 to will win trades.
Greater Glyph of Scaling Magic Resist x9 to be sure that their AP carry wont kill you mid/late game.
Greater Quintessence of Ability Power x9 to improve all of your abilities.
Masteries and Runes
The new mastery trees have greatly increased the viability of jungle Shen (as well as pretty much every other jungler in the game).
0/21/9 is optimal because now that the early jungle is so weak he no longer needs the extra offensive stats, also the extra buff duration is nice.
You can run whatever you want on Shen and you'll still destroy everybody, however these are the runes I prefer on Shen in lane.
Greater Mark of Attack Speed x9 to keep Ki-Strike up as often as possible.
Greater Seal of Armor x9 to take minimal damage in jungle.
Greater Glyph of Scaling Magic Resist x9 to be sure that their AP carry wont kill you mid/late game.
Greater Quintessence of Movement Speed x9 to speed up your clear time and improve your ganks.
The Route(s) [Doran's Shield or Ruby Crystal]
This section is for those who want to just farm their way to 6 as fast as possible while ganking whenever they can. You can start with either
Doran's Shield or
Ruby Crystal. Go Doran's if you want to accomplish a lot before going B; go Ruby Crystal if you want to get your
Heart of Gold as early as possible.
The routes you follow and the buffs you take depend greatly on your team lineup. Some games I will start by taking all the buffs for myself and hand them out later, other times I give them to my team at the very beginning, so as I go through the neutral camps I'll give both scenarios.
Blue Routes:
This is the fastest route to level 4.
Clear wolves, Blue, wraiths, twins, Red, wraiths. From here you can gank mid/bot or continue to wolves then gank top.
This is the fastest route to level 6.
Clear wolves, Blue, wraiths, wolves, Red, wraiths, twins, gank and/or recall, wolves, wraiths, twins, gank.
*After clearing red you can opt to clear twins instead of wraiths if you know you want to gank bottom after, as you will reach level 4 either way.
Red Route:
I recommend only using this route if you plan on giving red buff to your bot lane very early on, but it's a viable option either way. Clear wraiths, clear red but give to either support or AD carry, clear twins, clear wraiths, clear wolves, clear blue, gank or clear wraiths, clear twins, gank or recall.
There are other routes yet to be discovered I'm sure, but these are the two best that I've discovered so far.
The Route(s) [Boots + Pot x3]
The way that boots junglers work now is very different than before, it opens up more options since now you can pretty much do regular routes without a ton of ganks or you can be just as aggressive as before. The gank-heavy playstyle has been revitalized with the new "bank" system in the jungle hotfix (now the big monster at each camp gains gold/xp value each minute that it sits there, capping at a certain amount). This means that your camps are actually worth more if you ignore them in favor of ganks.
If you choose to speed farm, read the routes in the above section. If you choose to gank, start by clearing the wolves then blue so you hit level 2, then get into position to gank the nearest lane (top for blue, bot for purple). The other team will rarely see this coming (especially from Shen) and thus the element of surprise can lead to great success (whether by securing a kill or forcing them to use their Summoner Spells). But should it fail, you will fall behind very quickly if you don't have a plan.
So, whether or not the gank was successful, head back to wolves (gotta love that new respawn timer) and clear them, clear wraiths, clear red, clear twins, gank and/or clear wraiths, clear wolves.
Ganking
As the Jungler, you must know how to gank with Shen. It's a very simple process but it must be done perfectly in order to achieve successful ganks.
Communication between yourself and your in-lane teammate is crucial. You should check the lanes often for prospective gank targets; once you find one, tell your teammate (either through chat or by pinging the target) of your intentions before heading over (it is so frustrating when the jungler enters the lane and initiates the gank without letting anybody know, it almost always fails). Then allow the laner to let the target push the lane away from their tower. Once they have "cornered" your teammate, you should make your move.
Your primary tool when ganking is
Shadow Dash. The target will be taunted, disabling their abilities and forcing them to attack you. During this time you will hit them with the
Vorpal Blade and your teammate should begin dumping auto-attacks/abilities on the target. This should result in a kill which will grant you and your teammate experience and gold, also giving your laner enough time to clear a minion wave and go B to gear up before the enemy laner returns. This gives your team a great advantage very early.
If for whatever reason the gank fails, you should either return to jungling if you're still healthy, go B if you're not, or cover that lane while your teammate goes B if they got hurt too much.
Update Log
February 3, 2011:
Added an alternate Jungle Route, methodology for Dragon, and gold scheme; Wards chapter added
Pictures added lol
February 9, 2011:
Changed purchase items slightly.
February 13, 2011:
Added commentary on Warmog's vs Rylai's.
April 3, 2011:
Added "CLARIFICATION".
March 7, 2011:
Added Ganking chapter (between "The Route(s) and Wards"); Cleaned up the "Route(s)" chapter; Updated "Wards" and renamed to "Ward Control"; Simplified "New to Shen"
March 22, 2011:
Added Skill Order chapter (between "New to Shen" and "Summoner Spells"); Added more Summoner Spell options; expanded on Ki Strike commentary in "New to Shen"
March 28, 2011:
Added Aegis of the Legion to Situational Items.
March 29, 2011:
Modified Rune build, added optional Armor Runes and Swiftness Rune.
April 3, 2011:
Added "Clarification".
April 11, 2011:
Removed
Sunfire Cape from Core Build and moved
Aegis of the Legion from Situational Items to the Core Build.
Added
Greater Glyph of Scaling Magic Resist to Rune options.
April 15, 2011:
Removed
Heart of Gold and
Randuin's Omen from Core Build.
Added
Sunfire Cape and
Warmog's Armor to Core Build.
Added
Vision Ward to the Item Purchases
Updated "Item Composition" accordingly.
Updated Item Purchases (more organized).
Removed "The Warmog's Question", for it has been answered.
Added tip on using
Vision Ward in "Ward Control."
July 5th, 2011:
Updated everything to compensate for nerfs =(
September 16th, 2011:
Shen doesn't suck anymore, so I've updated the guide accordingly =D
Cleaned up Shen Basics, Items, Skill Order, and Masteries/Runes
Added Routes for Boots
November 9th, 2011:
Changed replaced non-smite spell on each build with
Ghost (because it's way too good on Shen).
Removed Fortify since it will be removed from the game in Season 2 =(
Updated both mastery and rune set ups.
November 16th, 2011:
NEW MASTERIES OP, updated accordingly.
Updated SS.
November 29th, 2011:
Jungle Remake; updated routes, masteries, and starting items accordingly.
December 19th, 2011:
Added Solo Top Guide.
February 13th, 2011:
Buffs on buffs on buffs.