Hi Im Scarredevolution a resident Bronze III n00b(I mean im really not that much of a noob as many bronzies are)
But aside from that this is a jungle lux guide and this is pretty legit man.
First your probably asking is this REALLY at all viable in any way possible in the current new Tank meta? First of all yes this is kinda sorta viable though it is a troll pick.
But aside of that this is just to explain how to make this viable haha.

Pros?
Your basically a roaming support
Can steal dragon/baron real easy
No one expects you to play jungle
Great gank potential
Can give away reds to top laners/mid laners or heck your ADC by the 2nd red.
Cons?
Mana starved and completely blue buff reliant so good luck if your mid laner is a jerk and decides to take blue from you.
Way to easy to level 2 cheese
Once again blue buff reliant so if blue buff is taken from you good luck
Squish as heck so the jungle will eat you alive

Jungling is very hard on Lux so you really need a beefy leash in the beginning i prefer to ALWAYS start at gromp to lessen the chances of blue buff being stolen

My path on jungling on lux is. Gromp(Smite it) -> Blue Buff -> Yolo gank or do Wolves -> Go back then upgrade smite if you can to rangers trailblazer and pick up pots -> Do red(Smite if emergency) -> krugs(Smite it) -> Then just gank :>

Honestly for runes just run the normal ol' magic pen reds/Armor yellows/Scaling AP or flat AP blues/and flat AP Quints.

So there aint much to explain here m8s.

I personally run 22/2/6 primarily to give my self damage/mana regen and move speed/and defence against the evil jungle of S5

Again just look at the top of the guide for what masteries to run ._. since thats what i run and it works well

Of course you will want to start with Machete then upgrade to Ranger's Trailblazer with Magus enchant.
Now Morrelonomicon vs Athene's Unholy Grail. People say get Athene's on Lux but in my opinion you should get Morrelo. In my opinion build Athene's if they have alot of Magic Damage so you dont get sh*t on when you gank or late game. Morrelonomicon in my opinion is the better option because of Grievous wounds effect so if they have a Mundo you can hinder his healing or heck this works well against ADCs so they cant just life steal to win.

Lich bane? Why lich bane? NO ONE BUILDS LICH BANE ON LUX?!?!?!?!?!??!?!? Well in my opinion Lich bane has been really effective lately on Lux when you have a Luden's Echo with it too.
The burst damage is just ridiculous with your passive(I sat there in one match and 2 shot a fed ADC with just E and an auto(Ty Luden's Echo)

Please do not play Jungle lux in Ranked play seriously leave this for normals don't ruin your team's chances by playing jungle lux in ranked.

To summarize Jungle Lux is legit pretty strong but not exactly someone you wanna play in ranked unless for some reason she becomes meta in the jungle.

I actually first decided to play Jungle Lux after one game I saw some guy play Jungle Morgana and do pretty amazing so I was like "I wonder how Jungle Lux is". My first game as jungle lux went badly due to being cheesed immediately.

In all seriousness though if you like Lux and are a Lux main I'd consider trying Lux out as a jungler just for fun :>