to make men free: a history of the republican party
Not too long, and to the point. If you are interested in how American politics got the way they are this is a great read, also highlights the shitty cycles of the republican party
http://www.amazon.com/To-Make-Men-Free-Republican/dp/0465024319
I think you need to move away from the idea that your will become either a conservative or liberal. This is seeking a solution to a predetermined answer. Instead ask yourself questions and seek out literature and resources that you believe will elucidate.
When I wanted to learn how the republican party became what it is today I read To Make Men Free: A History of the Republican Party
When I wanted to know about the political climate during the great depression and the start of WWII, and the development of the progressive policy known as the New Deal, I read FDR
When I wanted to know about the impetus to the current economic world order I read Keynes Hayek: The Clash that Defined Modern Economics and Free to Choose: A Personal Statement.
These books helped me develop a world view, but may be useless to you. Start with a question. Find resources to answer your question. Don't be in a hurry. Don't assume you will end your journey as either a liberal or conservative. You will find you are more complicated than a simple binary choice.
Personally, I would find a book on the history of the Republican Party. It's a really interesting topic to me. Specifically, how it was founded of anti slavery groups and leftists, and favored a large federal government. There were even a few radicals in the party that considered wage slavery to be just as bad as chattel slavery at the time. It may have even been the slogan of the party at one point IIRC.
Couple of books: <em>To Make Men Free: A History of the Republican Party</em>
<em>The History of the Republican Party (U.S. Government: How It Works)</em>