Welcome to my "No BS" guide. You want descriptions of his spells or items, look up. Be creative with the items depending on the opposite team. If you need reasons why the items are good, then you probably haven't read his skills/passive. Are there other items you can buy with him? Yep. Go ahead. Do it, I won't stop you.

First off, Lee sin = overrated.
Second off, Yorick = underrated. He's got the sustain to stay in the jungle over long periods (his creeps tank for you!.) He's got a lovely slow that is guaranteed to make people use their flashes early. He takes forever to die, and when he dies, he comes back! His ult is also insane. Ult your ADC, then you have two ADCs for 10 seconds (aka you win the team fight.) Timing is everything with that. You also have your Q spell, which yanno, is cool. It is great for the super damage of a sheen item. It's also good for quickly moving from one camp to the next.

Third off, you think lee sin's going to jump on you? Oh wait, you used your W which is chasing him, and now he's jumping/wasting his skills on your minion which is now hitting and slowing him as your spamming /l. This can also block other skill shots like Kha's and Kog's and Morganas stun.

Is he the best jungle? Probably not. But he is good if played well.

PS: I have played LOL since Beta, so yes, I get bored easily playing the same things over and over.

Pros / Cons

Pro:
Easy Jungler if your team helps you kill the first frog
Great survivability
Solid damage and HP
Your ult gives your team another ADC.
Late game it's VERY hard to die.
He counters a lot of enemy jungles (not only lee sin!)


Cons:
Huge snowballer. If no items, you suck.
You need a lot of farm, so can't gank too often.
VERY dependent on teamwork. Pray for good solo ques.

The new jungle can be pretty hard to clear, so you REALLY NEED A GOOD LEASH. The safe route is to start with smiting the frog (and hopefully your teammates don't steal yo XPs..) and then getting blue as you are very mana hungry. No need to smite blue though since he will give you all the mana regen you need after you get the buff. Quickly after blue get to red so you don't get it stolen. Try to gank at level 3 if you can. Repeat (make sure you don't get higher than level 3.)

Option two for you danger lovers out there would be to rush red as fast as possible, then gank their blue hopefully while they are still doing it (as they might have started at frog.) Yorick at level 2 and 3 is more dangerous then any other jungle. You can try to take advantage of that.

If you don't take Cleanse and teleport, u r teh noob.

Just kidding, ha ha ha ha. Take Flash and Smite like every single jungle because there is no other option. Everyone else will have flash, you will need it too, sadly.

Yorick has two build choices. It really really really depends on your team. If your top and support are pretty tanky, I'd go heavier on the AD. If your top is a megabrawler like riven then I'd go tanky on Yorick. If you have an ADC who is all skill shots and no auto attack like ezreal, I'd go more attack damage because ulting ezreal doesn't add much damage. Ulting hyper ads like riven or master yi or caitlyn is more important then ulting yourself (so now you're a tank.) If you don't have heroes like that, then ult yourself and get AD items. Capish?