There's a lot. Edmund Morris' trilogy is good but long. With TR there is a lot to digest: the youthful asthmatic side that transformed into a strong, intelligent man; the wilderness side; the political and military side. Just to name a few. Wilderness Warrior, while good, will give you a "biased" read on his development of "natural America" and not discuss so much of his political and military sides. The Morris trilogy will give you a thorough understanding of his life through a political lens but not so much about his relationship with John Muir and the conservation of "natural America." I would simply offer pick one and read it. I haven't read anything yet that painted TR in a negative light. He did so much good in his lifetime: the national forests, grew the Navy, held the New York Police accountable, just to name a few.
"River of Doubt" is a good book but not a biography. It focuses on one thing that TR did after his presidency.
There are also books that he wrote that may interest you: "Hunting Trips of a Ranchman" and "The Wilderness Hunter." Good reads, dated, sometimes hard to "understand."
I will also offer that on my reading list are "Mornings on Horseback" and "The Path Between the Seas," both which are TR-centric but may leave out details which you may find interesting.
When you read about him, just think - there's a reason we carved his face into the side of a mountain.