Leveling Balance is significantly easier than it used to be (particularly if you're using BoA items), but you will need significantly more downtime to drink. Past 40, Balance leveling becomes a bit more efficient, but you may want to save Moonkin for 58+ when Blizzard really put some effort into making the spec viable (and I say this as someone who did level Balance 40-69).
Leveling Restoration is not recommended. The Druid's offensive capabilities from this tree are designed to complement talents and abilities from the Balance and Feral trees. Unlike talents in other classes' healing trees (Tidal Mastery in the Shamans' Restoration tree is one such example), there's almost nothing here that increases your offensive output.
Macro and hotkey your forms as you get them.
For all I know, the readership plans on ignoring this guide and Moonfiring its way to 80, but if you do absolutely nothing else that I suggest here, macro and hotkey your forms. Successful management of the Druid is all about swift and fluent shapeshifting. Having to click in order to enter and exit forms is not only cumbersome, but also a death sentence in emergencies. Wowwiki has a more extensive list of useful macros here, but to boil the forms down to what you need for early leveling:
/cast Bear Form
Level 10. This becomes available after a short questline that will take you between the Night Elf/Tauren starting areas and Moonglade (for which you will be given the permanent and enormously helpful Teleport: Moonglade spell). Because Bear, Aquatic, Cat, and (as of patch 3.2) Travel forms all become available between levels 10 and 20, I'll shove them all into the next leveling guide.
/cast Aquatic Form
Level 16, and now trainable, although for nostalgia's sake I do recommend doing the original questline. As an FYI, it's only possible to cast Aquatic Form while swimming (i.e. your character can't just be standing in water), and you will be de-shifted as soon as your character can stand upright.
/cast Cat Form
Level 20 and trainable. You can find a Great Cat Spirit in southern Moonglade, hinting at Blizzard's original intention to implement a Cat Form questline akin to that of the bear's, but unfortunately that never happened.
/cast Travel Form
As of patch 3.2, level 20 and trainable.
If you want to leave whatever form you're in without having to use a caster-form only ability. As of patch 2.3, using a caster ability automatically pops you out of whatever animal form you occupy, but if you want to see the royal mess that Druid macros looked like pre-2.3, here you go.
Got your macros? Good stuff. Hotkey 'em however you like, then practice shifting back and forth when you get the forms themselves. This becomes second nature fairly quickly, although you'll want to experiment to find a set of hotkeys that are easiest for you to use.
If someone else doesn't want the gear and you can wear it, /roll
This applies more to 5-mans, but also to quest rewards and suchlike. Don't be shy about /rolling on gear even if you're not specced to use it, particularly if it's useful for tanking or healing. One of the major impediments to respeccing as a Druid is that each spec increasingly requires entirely different sets of gear. If there's a quest reward that's useful for a different spec, don't sell it -- bank it. If something drops in a dungeon and nobody else wants it, don't be shy about asking for it within reason. Remember, other people also build off-sets
.Don't be shy about offering to do something you're not specced to do
Don't pigeonhole yourself into one role so thoroughly that you miss out on valuable practice doing something else (I see a lot
of panic from Druids who leveled with one spec, then find themselves doing something completely different at 80, and this is why). Most normal 5-mans aren't insanely difficult, and are designed to be tanked and healed by people who aren't the "correct" spec in order to accommodate players who are still leveling. If a group needs a healer and you're Balance or Feral, feel free to grab your Resto set and go anyway -- ditto Balance and Cat.
The only spec where I'd be leery about doing this is tanking when you're not Feral. I've tanked as a non-Feral Druid previously and it is
possible, but a fairly miserable experience. To be frank, most of the Bear's viability is baked into talents, and you will have considerably more difficulty than your plate tank counterparts do while not explicitly tank-specced, particularly with respect to threat generation. Honestly, I wouldn't bother.
All set? Let's move on to rolling an actual Druid. The class is the most racially-restrictive one in the game, so if you're playing Alliance, welcome to the Night Elves, and if you're playing Horde, welcome to the Tauren. If you don't really care either way, most people pick the race they enjoy or identify with more. Neither possesses a racial ability that will make or break your endgame, although it might be more accurate to say that both possess racial abilities that are useful in the endgame, but are ultimately a wash once compared to each other.