Alright. So. As the title states. I need help jungling. I don't know what I'm doing wrong. But it seems like I can't do anything early game. The last few times I've jungled, I've gone 0-5 and then pick it up in the end if I'm lucky. I usually jungle with Jax, Nautilus, and Gragas. Any tips?
dont force yourself ganking if your laners dont do their part, farm up and try to intercept enemy jungler to mess them around, nautilus is very strong champ, aim for max cdr, E every 3 seconds for 440 dmg yes pls. Also correct build on him is 
the last item up to you, i get 
or 
, 
is fine too if you don't use CDR runes
I use Mpen reds, flat armor quints and cdr/lvl glyphs so i get max cdr with just and masteries those i use is 9/21/0
Also drop jax from your jungler list, gragas can use same build, cdr is most important offensive stat you can get on a tank (and defenses)
Keep track on jungle timers. You can give your blue buff to your midlaner, and it's a nice behavior.
Get to level 30. The extra runes + masteries help your clear time early, keep you healthier, and make it so you can do more things early. Building on that, having the right runes/masteries will also help. Maybe you're getting beat up early by the jungle? Grab some armor seals to stay healthier.
You may want to pick up some other junglers too. Those guys are fine, but usually picked in very specific situations. Jax for example has a very slow early clear and falls behind other junglers. You pick him when the enemy has some auto attacking split push monster like 
so you can 1v1 them later with your E (which dodges auto attacks). He's not the best for early game anything though!
Have a nightly jungling twitch stream where I talk about strategy, answer every question, and break down what I'm doing if you're curious: http://twitch.tv/gundaymonday
You may want to pick up some high damage junglers too, Kha'Zix, Rengar, etc. Just in case there's already enough tanks on your team or your other junglers are taken. Assassins are great at popping in, saying hi, and punishing the enemy laner for getting too aggressive.
Also, don't fall behind on farm. If there isn't a viable gank that you can go to, then feel free to just farm, counter gank, and/or go into the enemy jungle for some deep warding and camp stealing.
It may be tempting to run across the map to try and help, but you have to think about how long it'll take to get there and what you could be doing instead. Top lane may be having some trouble with the enemy laner and jungler, but that could mean an easy dragon for you.
Remember to save a charge of smite. Usually people use it on the raptors (chickens from hell) for the easy ward sweeping. You can scout an objective and make sure it's clear before going for it.
You shouldn't be watching your character too closely, try to keep an eye on the map to see who is over extended and where you can be to make the most difference; just poking your head in can make a person paranoid about going after your laner and if you're someone with high kill potential you might even be able to get their flash if they're afraid of you.
When it comes to farming you may want to learn timing your abilities so that you can get as much damage out of your champion as possible. Just practice setting off an ability right after you see that you did damage (AA ->E-> AA ->Q) instead of bursting and canceling a couple of autos that might have given you that extra damage you needed to kill the camp just a little faster.
Oh, and remember to learn your opponent's champion. Knowing who you can beat at what points in the game in various situations makes all the difference when you're trying to counter jungle or counter gank.
._. But I have rambled enough. If you've got any specific questions, I'm sure that people on here will happily reply, but I wish you luck in this ever evolving jungle.
