How to start jungling?

I'm to lazy to find the post about jungling. So I thought i might ask lol. I'm completely new to it and but I want to know how. And what kind of skills i should go for. Maybe if you can tell me what each God that's good at jungling should skill up first?

Ne Zha - Ring, Spear, Sash
Fenrir - Brutalize, Howl, Jump
Thor - Spin, Hammer, Rift
Loki - Decoy, Strike, Vanish TO START, Vanish, Strike, Decoy past level 3

In general, while this is a tip from a guy from League of Legends, the MOBA style is the same, so let me paraphrase his suggestion:
'Be the most efficient jungler you can be. Do not waste time waiting for something to happen, you'll end up losing opportunities and gold. Jungle. Kill every creep you can. Only when a clear opportunity presents itself, do you show yourself. Don't force plays that aren't there. React on plays that are. By this, you'll be far ahead of your opposing jungler, and you'll have many more possible plays by being more fed compared to him."

That is, always kill monsters (jungle minions, whathaveyou). If you have a buff, give it to an ally. But always, always jungle, because falling behind in levels and gold will ruin your ability to gank. Don't force yourself to get a kill in a lane if it isn't possible - wait for them to push to your tower, then go in and snatch an easy kill.

What items should i get first?

Generally, unless it's some outlandish jungle, you go with Bumba's Mask, boots, and some potions. Then follow normal god build paths (usually with some kind of lifesteal early on to stay in the jungle). Sell bumba's whenever you don't need it and need to pick up an item.

Thanks Raven!

I forgot to ask. Is it needed to jungle to the other side as well or do you just need to farm at one side only?

both

New question:
I recently started jungeling and doing decent mid/late game.
I always start with Mask and HoG.
I start with my team at mid harps, then going to red-->blue with the duo laners.
But I have following problems:

If duolane is on the other side of the mid harps, they usually don`t jungle with me and I`m alone from mid harps. When I clear another camp with HoG and skills I`m okay. But the next camp. I lose 70% of my life (or a bit less). Even with Bumbas Mask I can`t get enough health to constantly keep jungeling. How do I do that?
Simply go jungle till I`m low on health and port back? Harps at the bginning okay, but after that I need to get Buffcamps which are just too hard for me to handle?

How do I not die to creeps in early game!

Thanks for the answers!

@ Vaeldyn

In the situation where duo lane is on the opposite lane and duo/mid doesn't help:
Usually when I start off with Bumba's Mask, Hand of the Gods and a Potion of Physical Might I'm able to take mid harpies (let tanks tank), go red with the solo lane and pop Potion of Might and HoG it.
Afterwards go blue and let the solo help (It will be his blue afterall). Then go EXP and back.

Mh, is the early poiton worth it? Gonna try it ;)
Thanks! But more suggestions always welcome!