If you want a very forgiving jungler, play master yi.
You can feed on him, and still wreck face which is the beauty of him, as well as his simple execution. However he has the possibility to have a SUPER high skill cap if played correctly (like using W to reset autos and to reduce damage in a split second.)
Get Bloodrazor (Warrior for the on hit true damage as well as slow), Botrk, Berserkers Greaves, Guinsoos, then two tank items. This build gives you late game survivability as well as high tank killing potential.
Start with leash at raptors with Q. Then get E and take red. You don't really need to smite red unless you are afraid that your blue is under attack. Then take blue and get W. Max Q, E, W.
For ganking, you don't really provide anything but damage, so focus solely on attacking the enemy laner. Lanes where enemies are pushed up are really easy to gank.
Start by using your Warrior smite. This ensures a slow on your next attack as well as May force flashes. Then engage with Q. Activate E at the end of the Q duration and keep attacking. This should be enough to get kills early on, or at least force the enemy out of lane. Once you have ult, just add ult to the beginning of the "combo".
In early 1v1s it is VERY important to use your W correctly. It not only is a heal, but also a damage reduction (70% at max rank). Let's say lux has snared you. Just activate W and laugh at the amount of damage she deals to you, then proceed with the previous combo.
Playing Yi does take some practice, but once you've got the hang of it you can destroy your enemies.