I'd recommend "The Israel-Palestine Conflict: One Hundred Years of War" by James L. Gelvin. Everything is biased in some way, but this book is about as impartial as you can get when it comes to this particular subject.

The book I'm currently reading is called The End of the Palestine Mandate I haven't finished it, so I can't tell you how good it is. However, the premise of it is that several scholars wrote essays for it explaining the positions of the various major parties.

EDIT: Edited link to the correct edition.

Few things:

Mark Tessler's book. I'm on mobile and can't remember the name but a Google search of "Mark Tessler Israel Palestine" should bring it up.

Charles D. Smith's Palestine and the Arab-Israeli Conflict, best read alongside Benny Morris' Righteous Victims.

Listen to Professor Gelvin's lectures, available through The Teaching Company if I'm not mistaken.

Watch the full two parts of "The Fifty Years War", a 5 hour long documentary split in two that has amazing interviews with the decision makers themselves.

That'd be my study plan, and I'm fairly sure if you read at least one of those books and watched the documentary alone you'd be really, really well off relative to most of the world. Especially if you read Smith and Morris, they go all the way back to the Ottoman times to explain the origins of the modern conflict.

The Israeli Solution: A One-State Plan for Peace in the Middle East by Caroline Glick. The book is partly her promoting her new peace plan, but the first third of the book goes into a lot of detail describing the origins of the conflict.

I watched this four part mini series that was very well done.
http://www.imdb.com/title/tt1692202/

Tom Segev is a known Israeli author who has written some good works on the subject, like One Palestine, Complete or The Seventh Million(on the impact of the holocaust of the politics of Israel). Benny Morris has written the (in)famous 1948 in which he looks into the Israeli archives to see what really happened in the war of 1948 with regards to forced displacement or killing of Palestinians. The Israeli historians who belong to the New Historians are generally good to read, because they represent a movement in the Israeli academic world to look again at Israeli history.

If you want to read on motivations, I would actually suggest you read memoirs or literature and move away from searching impartiality, just make sure you read from all sides.

Edward Said is not only a scholar who became famous for his work on Orientalism, but he is also a Palestinian who had to flee in 1948 and if you look into his work, there are a lot of small books that cover his personal views on the Israel-Palestina conflict.

When it comes to literature, there is a lot to choose from. The Secret Life of Saeed by Emile Habiby has been popular and gives a good insight in the dilemma's Palestinians with Israeli citizenship face.

If you want to know the motivations of people, read what they say themselves, so look for literature or memoirs. I only gave a few examples, but there is a lot around.

For documentaries, The Gatekeepers(2012) on the directors of Israel's internal security service or Five Broken Cameras(2011), a Palestinian filming his life with Israeli settlements close by, spring to mind.