Hi! This is my jungling guide to Riven covering her whole game and explaining on why her build fits her the way it does etc etc. Before you guys start flaming me for having another "omg trinity again" or "omg another tanky dps jungle" just read the guide before casting judgement upon little ol' me. If in doubt cause I'm not some high elo dude, then try it out yourself and make a decision, elo doesn't equate to everything.
Apologies if the guide is a bit messy, I'm not familiar with the guide tools.

PROS:
She's CDR based
She's very strong throughout the whole game
Riven brings a lot to the team, be it huge amounts of damage, or her stun, or her knockback, she's able to rush into the carries and take them out quickly, another tanky dps.
Albeit her E isn't a true gap closer, it's still pretty unique and fun, giving you a shield, and helping you chase or escape.
Her Q Combo is another original skill, strong and fun.
Has a killer ult "KILL THE RUNNER"
She looks soooo COOOOOOL

CONS:
I'm unable to tell if shes a girl or a guy
Her range on W is really small and needs getting used too
Her E can be annoying sometimes and not go all the way

Personally I run the old Flash+Smite
Recommended:
Flash:SINCE EVERYBODY USES IT NOW and cause Riven can get kited quite easily, Flash allows for a quick initiate/escape
Smite: THIS IS A JUNGLING BUILD, TAKE THIS OR GET OUT. Faster jungling, easy steals, preventing steals all the sort.
Ghost: Too consistently chase/escape, much more reliable than flash in my opinion.
Exhaust: Riven again can be kited easily, and exhaust allows for you to unload your combo in relative ease. Not my cup of tea but w/e works for you.

I take armor pen marksbecause it helps deal true damage in the jungle and for more damage in the jungle. Alternatively you may useto get the most out of the lifesteal/and clearing the jungle faster. It's a preference if you want to have a safer/faster jungling, then take the strength runes.

The armor sealsare a no brainer to any experienced jungler. Armor seals are essential to any and all junglers to be dealt less damage in the jungle, it helps so much in the early levels of jungling and without them, it's hard to stay in the jungle without dieing.

The glyphs are just personal preferences. Magic resist glyphsare very good for late game or you can use the cdr glyphssince you are completely cdr based, and it'll help speed your jungling and help throughout the game.

The Quints can be eitheroragain for the same reason. I recommend finding a balance between the two. I.E. attack damage marks and armor pen quints, cause the armor pen allows you to deal true damage while the attack damage speeds up your jungle significantly.

I take a standard 21/0/9, letting her true offensive side show, while taking the all important Utility taking the Awareness mastery to keep up in levels in the jungle, very essential and the buff duration increase, both important as a jungler, yet still able to deal an insane amount of damage.

Start with a Vampiric Scepterand start at wolves. (Yes I'm essentially taking Stonewall008's route so credits go to him.) Q and auto attack between each Q and auto attack the wolves too death. Then go run to Wraiths and smite the big blue wraith and level up W, and kill the wraiths. Now heres the slightly difficult part. If you decided to take all armor pen marks+quints then you'll have trouble with the duo golems as I frequently do. Apply the hit and run tactic so you only fight one golem by running a little back and leading it on, then attack it. Release your whole combo, rinse and repeat on the last golem. If you cannot kill it, just leave it and b, it's not worth dieing over. Once back at base, pick up a cloth armorand a health potion or 2
Go to blue golem and kill it popping a red pot in the process. Kill the wolves, kill the wraithes, kill the red golem, kill the duo golems. And that's it for the standard route.
Remember that your not tied down to this route thick and thin. You can incorporate what you want, be it counter jungling, or ganking. Ganking and warding is important to any jungler. Help any lane that's enemies are overextending and punish them for that. Although normally I tell my team to play it safe until I can get red buff before I can gank for them. Play to your strengths.

I cannot stress this enough, time your smite, unless you want a stolen buff/dragon/baron from you, I advise you drop the monster low enough and smite. An analogy would be Pokemon, GET THE POKEMON LOW ENOUGH AND THEN CATCH IT WITH YOUR POKEBALL. OTHERWISE YOU GO HOME CRYING.

Wriggles Lanternis quite possible the best item on any jungler. It speeds up your jungle, gives you more armor/damage, has it's awesome passive proc, and sustains you with lifesteal. Even better, a free ward every 300s, its an overall good item, get it.

Here comes some controversy. Should I get Mercury Treadsor Lucidity Boots? Or maybe even Ninja Tabi nikesIt's very situational. Normally I will get Merc treads for an ap-heavy team or one with a ton of CC. It helps so much with Riven's survivability. If there is little to no cc and the team is balanced in both magic and attack damage, Lucidity is an option, not my favorite boots but still viable. Ninja tabis for those AD heavy teams, especially when they get fed.

You want to take advantage of the AvariceGP5 ASAP. The crit chance is nice and you're going to need to have it for youmuu's anyways, might as well get some gp5 out of it.

SHEEN, YES IT GIVES RIVEN MANA, I lol everytime I look at my 250 mana bar. Anyways no, Riven doesn't utilize the mana or ap, but heres several reasons why its so good on Riven. Riven's whole kit seems to have been made for this gem. It's active can be procced with Q a total of 3 times, then with W and E too. If timed with Q right, you'll deal insane damage. Not only that, but it works with Riven's passive too, a huge amount of pain.

The Trinity Force, no you're not gonna build a Lich Bane. This item is CORE on Riven. She uses everything except all that was stated in the sheen. The sheen proc, attack damage and more hp, a 25% proc slow, crit chance, attack speed, and MORE MOVEMENT SPEED. This item is so important on Riven I cannot stress it enough. It allows Riven to move in and out of fights with relative ease with her E and Q and movement speed. It's simply amazing how fast she can be. Yes I realize that some people prefer Frozen Mallet, and it's a good item to be sure, 100% slow and very tanky with a little damage. But Trinity offers so much more on Riven, and in the game below somewhere in this guide, I did play against a Frozen Mallet/dps Riven who laned. She got super fed however in late game I completely wrecked her and her team because I could run in and kill all their carries(Riven included) and run out quickly. She even was so fed to have a youmuusand an Infinity Edge too. She was unable to deal enough damage to kill me, even when she used youmuu's (cause I always forget that I have it too) and I always ended up the victor with my tri-force combo nuke.

The ghostbladeis quite a nice item for any ad jungler, it helps so much especially on Riven, while having the active is great, it also shines in giving you CDR, armor pen, attack damage, and crit chance. What's not to like?

I used Force of Nature in this particular gamebecause they had 3 champions dealing magic damage and because FON is a great item overall. I was able to heal my full hp after a fight in a matter of about 30 seconds running around killing stuff with my lifesteal and my FON passive. However the most important thing about this item is the MOVEMENT SPEED it gives. My build is not only a tanky damage dealing Riven, but a fast mobile one too, quite like poppy. Riven is simply a fearsome champ who can be easily kited, however thats not the case with her E+Q and the movement speed. You will catch your prey unless its like Ashe or Shaco.

Truthfully, I was reluctant before about getting Warmogssince I learned how armor/mr truly worked around a year ago. However I've learned that a perfect balance between hp and defense is very tanky indeed. This combined with FON passive+lifesteal I could recover from any fight without having to back.

I have around 4k hp with 480 ish Movement speed, and 250 mana, with around 100+ armor, 170 ish MR dealing incredible damage to everyone. I simply couldn't be done in. The end result left me having the most gold, a gap of about 5k gold from the next richest, and the most cs out of everyone too. The most kills most assists least death etc. etc.
This guide will not guarantee you carrying every game you play, but this guide is to allow you to broaden your options playing Riven, and show you another established method to playing her.