Master is one of the most popular junglers between starters, as it has a low price, and is OP.
One of the best assassins, Yi depends on : Movement Speed, Atack Speed, and AD. But, as good part of assassins, he is squishy (Not if he levels W) and depends on getting kills.
It has good clear-jungle, being viable start at any buff.

Master Yi can get up on the opponent pretty quick and burst him. His gank combo is basically R+(Blue Smite)+Q+(Red Smite)+E,but if you go through the tribush, you can save your ult to burst your opponent. After ganking (If succesfull), you MUST push the wave, as your opponent doesn't get XP or gold.
Don't be worry if you get the kill, you are a Master Yi, he gets good with kills.