I spend a fair amount of time these days, browsing the Official WoW Forums.
I read the Guild Relations board first and with most interest, because there's often some interesting discussions going on from an Officer/Guildmaster perspective, about the varying challenges of running a guild. And for some reason, there don't seem to be many inflammatory "trollers" in that forum (just posting inflammatory things to stir people up), which means the "signal to noise ratio" is high. Less annoying, more information.
I then tend to venture over to the General board, just to see what the topics of the day are. Here, I find a lot more trolls and a lot more trash posting (Subject: "Blood elves are ruining the Horde" Body: "Discuss"), but on occasion I find some very interesting reads.
Next, I hit the Raid %26#038; Dungeons forum. Everyone's talking about the heroic and other level 70 dungeon stuff that it'll be a long time before I ever see, but world of warcraft is that board educational. Wanna get the hard and fast on what mistakes folks in your class tend to make while in dungeon groups? Check this forum out. Wanna know why certain spec builds are looked over for the Burning Crusade 5-man dungeons? You'll get lots of info there.
Sometimes I venture over to different Class forums, to see what's going on there. Again, there's some GREAT information about class abilities, tips and tricks for successful solo play vs dungeon instance play vs raiding, and a lot of heated debate in general.
I've learned so much just by reading the forums. Of course, for the 10% of good information I glean, there's 90% I have to ignore outright.
Specializations Before 40 - Skill First, Efficiency Second
One of the big things I've learned from the forums is that specializations only really start to matter quite late in the game.
While yes it's nice to have a "protection tank" and "holy healer", it's not required, because at the levels where instances can be taken on by players higher level than required, success is more about the "dungeon party skill" of the players in the party, and less about squeezing efficiency out of the tank or healer's powers.
That's not to say that a player can't slow their progression down by speccing poorly, nor to say that certain specs don't work better with specific other specs... it's just to say that learning how to play your class well (in a party situation which is different from solo play) is an important first step, and then fine-tuning your class play through spec(ialization) is something to focus on later.
Purpose of Specializations
First of all, you choose your Specializations by spending your Talent points ('n' brings up your talent trees). The very basic purpose of a 'spec' is to allow a player to 'tune' their characters so as to be somewhat unique from others within their class, depending on their own play style and needs.
The first time I spent my Talent points as a levelling Hunter, I spent points according to where I felt I needed a boost in my gameplay. Pulling aggro from my pet, or my pet dying too quickly? Put points in Beastmaster. Fights lasting too long? Put points into Marksmanship. At the end, I came out with a predominantly Beastmaster talent spec but I'm sure it wasn't "THE Beastmaster spec".
The beauty of Talent specs is that you can get them wiped (for a fee) at any of your class trainer locations, and you can re-allocate the points in a different fashion. If you've got the cash to spend and want to try some other talent specs, have a ball!
All Classes Are Hybrid Classes
Some may argue that not all talent point configurations can really be called a "specialization", due to the true definition of that word. If, after all, you put an even amount of talent points into all three talent trees, are you really choosing a "specialization"?
But at the same time, whatever your Talent configuration is, that's your "spec". Funny.
At any rate, because of this imbalance, it can truly be said that all classes can be configured as Hybrid, meaning they're not truly strong in any one tree of potential specialization. For some players this may be a "gimped" playstyle (especially in dungeon/party situations) but for others it may work perfectly.
That's all I have to say about that, for now.