I use Armor Penetration marks and Quints, Armor Seals and Mana Regeneration per level Glyphs.
Masteries don't matter that much, 9/0/21, 11/3/16, 21/0/9 are all viable options, it just depends on what you prefer.
Smite, no discussion here
Ghost, my personal preference
Exhaust, can work vs a lot of physicals or for better chasing, especially if you can't garantee having red buff
Cleanse, vs a lot of hard CC (Stuns, Fears, Taunts)
There's a few ways to do it, I generally prefer to get a cloth armor first and get some health potions (just get 5 if you're new at this).
Build this into a Madred's Razor (usually upgrade this into a lantern unless you expect to need a bloodrazor later on), pick up an early vamp scepter (and of course boots of speed) too, even if you aren't getting the lantern. Lifesteal keeps you from having to recall often which speeds up your leveling.
After this there's a bunch of items that work well on Yi, I usually start off with a Zeal for the extra movement speed and attack speed. Youmuu's Ghostblade and Starks Fervor are great items for Yi too, and if you need more health and find yourself without red buff often pick up a phage and upgrade it to a mallet.
Jungle order for Yi is a little different than most junglers (everyone seems to start at Blue regardless of their champ these days).
I usually start at the small golems, using alpha strike on them and killing one with smite (unless your alpha strike procs the extra damage on both of them) then head to the wraiths, do the wolves and then get the blue buff (smite should be up for this again).
After getting blue, recall and buy a long sword, boots of speed or a vampiric scepter (depending on what you think you'll need most, generally the vamp scepter will be most helpful but getting boots allows you to pick up an early ward.
Head to the red buff camp on your side and after killing it look for potential ganks.
E/W/Q (i generally take E but taking W allows you to buy less healing potions at the start whereas Q has the highest jungle speed potential)
Get R whenever it's available, the order after this is really up to you (i prefer maxing out e first and then q, taking one or 2 levels in w if my team is unreliable).
That's pretty much it, Yi's a fairly easy and potentially super fast jungler as well as a potential hyper carry especially in solo q, good luck!