When I first started learning about Arminianism, I didn't know who I should read. There wasn't much out there at that time and I didn't know where to go, so I just read Arminius himself. That was hard. He's very good, but I could have used an introduction first. Here's a few books I have read over the years, and if I had to do it over again, I would have read them in this order:
Intro to Arminianism - Just Getting Started
1. Arminian Theology - Myths and Realities by Rodger Olsen
Great at explaining what Arminians believe and don't believe.
2. Life in the Son by Robert Shank
Excellent Exegeses of most passages dealing with falling from grace.
3. Free Grace a sermon by John Wesley
Gives a short critique of Calvinism.
Intermediate Arminianism - Putting the Pieces Together
4. Why I am not a Calvinist by Jerry Walls and Joe Dongell
Strong systematic approach and solid Arminian reasoning.
5. Elect in the Son by Robert Shank
A case for corporate election.
6. The Works of James Arminius
Your now ready for the big dog. He may yet be a wild ride, but give it a try. As far as putting exegeses, systematic theology and sound reasoning together, I haven't found anyone better.
Advanced Arminianism - If you Like to Ask Why, Why, Why Like a Three Year Old
7. God, Creation, and Providence in the Thought of James Arminius by Richard Muller
Great at walking through God's attributes using Arminius' reasoning.
8. The Only Wise God by William Craig Lane
Readable, thoughtful, reconciliation between God's foreknowledge and freewill.
9. Redemption Redeemed by John Goodwin
Detailed study on the Atonement.