So I have Morrigan in my party, and I'm wanting to make her a spirit healer. Her default specialization is Shapeshifter, but I bought some book (for a lot of money) at the shop in Denerim that said it opened up the 'Spirit Healer' specialization. How does that work? I've levelled up, but it did not let me do that (I don't have any specialization points). I figured this book would give me one - to put toward spirit healer. Anyone know how this works??

Those books just unlock the specialization for future use. You get a spec point at level 14 for party members.

No, you can only dump points into specializations that you have unlocked. Also, when you unlock a specialization it stays unlocked for future playthroughs.

I believe spirit healer is unlocked by recruiting Wynne and talking with her similar to how Templar is unlocked by talking with Allistar.

The books just unlock the possibility of choosing that class.  You can't actually earn specialization points until level 7 and level 14.
 
By the way, after you buy a book you can reload to a previous save before you bought it and the class will still have been unlocked.

Okay, got it. Thanks everyone. Yeah, I did talk to Wynne, but the conversation was . . . very brief :)  Needless to say she's not in my party.