To really understand Thomas Jefferson, you need to read his own words. This is the most useful, concise collection of Jefferson's letters, major writings, and public papers and addresses.
Ellis offers solid scholarship and highly readable prose in this analysis of Jefferson's character. Ellis does not get lost in the mythology of Jefferson; instead he explores the curiosities and contradictions within Jefferson's thought and life from his arrival on the public scene in 1775 until his death in 1826.
This is a useful and wide-ranging collection of generally readable essays on the "revolution" represented by Jefferson's election. While several essays explore the impact of Jefferson on American politics and culture, there is also an emphasis on the international developments that framed, and even made possible, Jefferson's election.
Published shortly after the release of the DNA evidence solidly establishing a sexual relationship between Jefferson and his slave Sally Hemings, this collection of essays by Jefferson scholars provides an interesting introduction to the significance of this relationship. Some of the essays within the collection focus narrowly on Jefferson, others examine the broader context of interracial sex in Virginia, and still others look at the human legacy—the lives of Jefferson's and Heming's descendents.
For the nuts and bolts of Jefferson's presidency, this volume of the American Presidency Series published by the University Press of Kansas is extremely useful. Straightforward in its purpose and prose, this short book (200 pages) describes Jefferson's presidency from its chaotic beginning to disappointing conclusion.