I have been trying to read more about the former president, as I think he is simply fascinating. However I've recently encountered books that have a bit of bias - i.e. "Theodore the Great: Conservative Crusader" by Daniel Ruddy. While I have no issue with people pleading their case about what they think T.R.'s ideals were, I just want to find the best and most detailed books about his life and his political experiences from an unbiased (not pushing conservatism or liberalism) viewpoint. If anyone has any recommendations please let me know!
Leaving aside the issue that anything you read is going to be biased, the go-to recommendation for an overview of Roosevelt is Edmund Morris' trilogy on Roosevelt -- it clocks in at about 2,500 pages, but is a good read and good overview of Roosevelt. Morris has worked as a journalist, not a historian, but the trilogy does include notes for his sourcing and a bibliography, which you can mine for further reading.
I recently read Doris Kearns Goodwin's The Bully Pulpit which is about Roosevelt and Taft. I thought Goodwin did a pretty good job presenting the facts without taking a side. It talked about the bad stuff Roosevelt did like the Brownsville Affair and the good things. Same with Taft.