Skill-Capped, Virkayu, and Kingstix all have wonderful guides for learning the Jungle.
Evelynn and Zac have the exact same standard route, starting Hunter's Talisman, Red Buff, into Krugs and Raptors for the Lv3. From there they either continue full clearing or they Gank Mid. Afterwards they will take control of Scuttle.
You can turn this around by doing Raptors before Krugs, which opens up a really early side lane gank. Transition this into stealing the enemy's Blue if you know they haven't started on it, or if a gank isn't available, you can back, go to your Blue Buff, Scuttle should be up, and then full clear from your Gromp to your Krugs (Raptors and Krugs should respawn just as you get to them, for an efficient clear).
Zac can also do a 4 camp interior clear if you just want a simple side lane gank.
Try to time yourself so you back 30 seconds before your Krugs respawn. It is imperative you farm them off cool down to maximize your farming potential.
For items, build
or
before you buy anything else, then straight into their completed Jungle items. Otherwise, just follow any online guide.