Please note that I leveled my druid back in like... vanilla and TBC, so my info on druid leveling is pretty outdated... However -- At your level, you'll really want to abuse swipe. It does kind of suck given it's cooldown, but just use it every chance you get, think of it like HoR -- you'll probably use it non stop until the northrend~ content.
The thing with druid rage is that you only get rage when you dodge or crit, if you have the talents, but at your level it's sort of a crapshoot.
Try to save your rage to use on swipe, and if you hit 80+ rage go ahead and use maul (make sure it's glyphed), otherwise don't use maul all that often. Remember that Mangle can hit really hard as well, for instance if you've lost a mob try to mangle it before you waste a maul.
Druid tanking -- tanking in general really -- is getting some major changes come Mists (frankly I'm not enjoying most of the changes) so a lot of what you'll 'learn' won't be applicable in mists, but in Cata at least once you hit 81 (when you get Thrash) your rotation will look something like this (you get lacerate at 76~ or something) --
Mangle on Cooldown
Laceratex3>Pulverize (keep crit bonus up as much as possible)
Thrash/Faerie Fire as filler (swipe is no longer good dps on single targets)
Spread lacerate around and/or mangle -- thrash hits harder than swipe and with threat being really easy your goal should be damage. If you can get a laceratex3>pulverize in go for it, but I find that difficult to do nowadays with people as geared as they are.
Spam Mangle, make sure you tab over if there are 4+ targets (so you at least hit them a couple times)
If you have rage, use maul as well
In my current gear berserk+mangle allows me to, basically, take down a pack of monsters by myself once every 3 minutes. I've found that berserk mangling as a bear is like the most satisfying thing to do as a tank, since it lets you dish out some serious dps in good gear.
Other stuff --
As you level try to get your hands on some expertise, there's a relic with a gem slot you can pickup out of stratholme and slot with a wrath epic expertise gem that can help a ton. Hit can help a bit too, missing a swipe or mangle can be really annoying at the lower levels.
As for rage the only thing you can really do is use Enrage (I don't know if you get that at a lower level or not though) or just pool it, when a pack of monsters is getting close to dying, stop using attacks and just let your rage build up for the next group. Just auto-attack and let your rage fill up. Also don't be afraid to smack one of those critters you see in dungeons, if it's good enough for warriors, dammit, it's good enough for bears! Hehe.
Oh and don't use charge, it's a waste of rage and it's mostly worthless. Make sure you don't waste talent points in "improving" it either, they're better spent elsewhere. Charge is alright if you've got rage, but absolutely under no circumstances should you use it to start a fight when you have low/no rage. It's also useful to use to get to a mob that's running away/caster mob that won't move/melee mob running after a dps/etc... but remember that unlike a warrior it costs rage to use, and at lower levels bears really need that rage for attacks.
I also believe you have access to Furor, which you can shift in/out of bear form to quickly generate 10 rage at the start of a fight -- you can macro it via:
/cast !Bear Form
Mostly it sucks as a bear in regards to rage, and doesn't really get better until you pickup a couple of talents (and frankly even at max level I find myself rage starved on occasion). But cool thing, though, is that you can do some crazy dps as a bear sometimes.