Start by buying the hunters machete+ward and choosing W as your first ability, that gives you extra damage against multiple jungle enemies and the item gives some life steal to survive. The first monster you should kill is Gromp( You can smite gromp and the golems early on because then you will get its special buff to kill them faster with). You will get a level-up by killing it and you should choose q as the next ability, after that you can move onto wolves. After you kill wolves you can also get the Birds but you will be left with very low health. I encourage you to kill them because then you get level 3. You should take the E aswell and get to the bush and nexus. Regenerate and get the Hunters talisman. Now is the time to check the lanes if you can gank somewhere. Always try mid or top lane first because they have only one enemy to deal with, so they are safer. Always check the lanes from time to time if maybe the enemies are low or you have a good chance to help out while you return to the jungle. Then you should get blue and red buff and clear the jungle for awhile, always keeping an eye on the lanes.
Your team will start hating you if you do not gank ALOT because mostly you will be playing with egoistic teenagers who think they're Bjergsen.

After you reach level 10 or the timer runs to 20 min you should start teaming up and pushing lanes with your "Buddies".

If you get good ganks and everything works out fine, then you should have enough HP to deal with multiple enemies by yourself. So YOU should be the one to jump in first with the R/Q swinging your W around, and slowing the enemies down as much as you can with your E. Your team then can easily start picking the enemies off, because you have high HP and defence so you wont die that easily . With the W, cindra and sunfire cape the enemies will get Tons of damage from you by you just standing near them.

You will not be very good at soloing towers though because your basic attacks don't deal that much damage. So stick with your ADC or team as much as you can. With your warmongers you can go and wander around in the jungle for awhile after fights, to regenerate your HP and mana pretty fast.

If you follow these small tips you should be able to win many Games.

GL and much GGs in the future.

Check Youtube.com/videogamedunkey for more tips and tricks.