What philosophy books are good for an new person to philosophy? Philosophy in general, not specific branches of it.

I tried learning Philosophy in high school once.  My friends were clearly gifted thinkers; they  could easily analyze certain situations and deal with them appropriately. I struggled to grasp any concepts they had about anything. I remember one point in our meetings where our focus was that Freud wasn't actually a real philosopher, and I did not understand a single bit of it.

In short, I don't know where to start.  There are just so many philosophers out there, so many of them with different ideas, Voltaire, Locke, Nietzsche, Socrates, etc., where do I go from here?