Anakin's fall to the dark side and his redemption is an interesting one, and one that is very complex.
I think that the films contained traces of the story, but on the whole, the expanded universe has the story more fleshed out.
I don't think Anakin "knowing his destiny" ahead of time contributed to his "fall" to the dark side (I don't think Anakin ever truly fell to the dark side, and I think one can make that argument for a great many sith, but more to come...)
Qui Gonn mentioned in the films that normally force sensitive children are detected at birth and taken from their parents, then raised at the Jedi temple. Anakin, however, grew to, what, twelve? Because of this, Anakin developed relationships, he learned how to make relationships, and those become important to him. His mother, his friends, C3PO, etc. He was fulfilled by those relationships, and had a sense of loss when he lost those relationships (first loss when he left Tatooine, big new relationship when he met Padme).
Meanwhile, his Jedi peers were being raised in the Jedi temple. They learned compassion for all things a general sense of goodness, but in a non-attached way. Beings live, beings die, life goes on. You should feel for all living things equally, none more than the others.
Now when Anakin starts training he has a goal. Be strong to save his mother. Be strong to liberate his friends. Be strong to save padme. As the clone wars began, Anakin was known for rushing into battle AHEAD of the clone troopers that he commanded. The other jedi, sure, had a sense of trying to preserve life, but if clones died here or there, it's part of war. Tragedy, but life goes on. Anakin, however, felt personal attachment to life. He didn't want any clones to get hurt/killed more than needed. As the clone war progressed, he wanted to be powerful even to protect his master, Obi-Wan. Anakin believed himself strong enough to protect even his master. Could it have been his head filled with prophecy? Maybe. But it's also youthful pride, and the fact that he was very talented in the force.
The first hint of tragedy came with the death of his mother. All of his training, all of his power, useless. Of course, other Jedi could not commiserate with him. No Jedi in existence at the time had ever had a relationship like Anakin had with his mother. Jedi advice of "all life moves on and becomes one with the force" rang meaningless and hollow in Anakin's ears. And so, he wanted to become even more powerful. Powerful enough to stop people from dying. To the jedi, that was selfish and "evil," but for Anakin, it was the ultimate sign of love.
All this time Anakin's relationship with Padme builds, a relationship which the Jedi order cannot fundamentally relate to.
Tragedy comes inching closer when he sees visions of Padme dying. For Anakin this is particularly hard, because the memory of his mother's death was such a big blow to him. Of course, when he seeks advice of the Jedi council, and Yoda specifically, he again gets canned Jedi advice... all beings join the force, beings live and die, life goes on, etc etc. They have no way to relate to Anakin because they have never had relationships like this. Of course, they are troubled by Anakin's "lust for power". Because if you want power, you OBVIOUSLY want it for selfish means. The Jedi are totally oblivious to those that exist outside of their order, and Anakin is an honest (and still fundamentally good) anomaly.
In comes Palpatine. Palpatine doesn't outright encourage "evil," but does not condemn Anakin's pursuit of power. In fact, Palpatine SUPPORTS Anakin's pursuit of power. At some point, Palpatine puts Anakin on the jedi council (an unprecedented move in history).
The council is wary (more for Palpatine's play for power), but Anakin is ecstatic. Why? Because jedi masters (the only ones allowed to sit on the council) have access to restricted areas of the Jedi library, which contain holocrons that document "hidden" or "forbidden" force powers. Powers that he believes he can use to save Padme.
But the Jedi council denies him mastership. Anakin is frustrated and angry. The Jedi, of course, chalk this up to his youthful ambition, which is becoming more and more out of hand. They believe they need to reign him in, prevent his ambition from becoming dangerous. But what they don't realize is the more they deny Anakin, the more they think they are doing him a favor, the more they HURT Anakin. He is pursuing power, but NOT for selfish reasons- in fact, quite the selfLESS reasons. The Jedi do not realize this, and so Anakin becomes more and more desperate. Again, the Jedi's ignorance is at play.
Finally Palpatine reveals himself. A dark lord of the sith. But is he really so bad? The Jedi have prevented Anakin from gaining knowledge at every turn as they dogmatically deny relationships as well as power. Palpatine, however, has been a patient mentor, helped him where he could, and encourage Anakin to "do the right thing" regardless of "dogma." Anakin does not see the "Sith" as a selfish and evil group. Instead, he sees them as an independent group that will let him accomplish his own (good) goals.
And so Anakin "falls to the dark side." I don't like the way the films portrayed him hunting down the jedi- basically killing a bunch of kids. Anakin was a powerful Jedi, powerful enough to rival the Jedi council members, both through training, raw talent, and determination. Anakin took on multiple jedi knights and masters and beat them all, both through swordplay and force powers, before his operation and after. In any case, he saw the Jedi as an oppressive organization that was literally allowing his mother and wife to die, so when he says to Obi-Wan "from my point of view the Jedi are evil," he really does mean it.
And, of course tragically, his own wife and child (he doesn't know they are twins), die.
So he has lost all of his friends, all of his family, and all he has is immense force power and control of the galaxy. For what?
This is exactly what Palpatine desired, because while the Jedi believed that love and attachments would lead you to selfishness (and ultimately actions committed by Anakin) the Sith believed that love and attachments led to weakness, ultimately preventing you from doing what you needed to do even if control of the galaxy was within your grasp. As long as a loved one was standing in your way, you wouldn't do what was necessary.
So Palpatine gains control of a powerful asset, and Anakin/Vader is just... well he just keeps living, because why not.
And then comes Luke Skywalker. When Anakin realizes that his son is still alive, a product of his ultimate love for his wife, his purpose for living comes back again. And this is why I say that he never really "fell" to the dark side. He was ALWAYS fighting to preserve his family. It's why it was so powerful when Luke declares "I am a jedi, like my father before me." Palpatine thought that Anakin was truly his pawn, but when confronted with the choice between serving Palpatine and killing Luke (who wouldn't turn to the dark side), he chose to kill Palpatine, thus coming full circle.
And so the tragedy of Vader, Dark Lord of the Sith, comes to a close.
Luke, when building the Jedi order anew, learns from this, and has a far less strict set of rules regarding interpersonal relationships than the Jedi order over which Yoda presided.
But of course there were Sith that came even out of that era, and with similar motivations to Vader.
In any case...