First, ofc start with cloth armor + pots, then rush madreds for faster jungle clear time and boots of speed for more effective ganks.

After that you should go for a g/10 item such as hog or philo. Continue by clompleting the wriggels lantern, then go for brutalizer or phage, brutalizer recommended for more dmg output due to the arpen, even though i only would recommend this if you have a permanent red or hard cc on the lanes which you have to gank. Buy the other one right after.

Next you should either finish your frozen mallet for the slow --> even harder ganks + tankyness or the infinity edge for sick dmg.

Once you finished both upgrade your brutalizer to youmoo's ghostblade and change wriggels and hog/phile for an atmas and a maw, to become even more tanky.

Either go for Q or E first, if you max E first, you will have a higher burst on the start of a gank, which is quite usefull, whereas if you max q first your constant dmg is higher and you are more useful against single targets over time, also its more effective vs blue + red buff, so if you play a gank-intensive jungler rather go for the e, otherwise i would prefer maxing q first and max e by lvl 13.