The first three are really general textbooks on Roman history, but are the best overview and world impact works. The remaining books address very specific topics concerning or relating to Rome. They're more interesting, and easier reads, but give you far less information.
* C. Starr, A History of the Ancient World , 4th ed. (ISBN: 0-19-506629-4)
Starr's book is a broad history which puts the development of Rome in the context of the entire ancient world.
* lan Ward et al., A History of the Roman People , 4th ed. (ISBN: 0-13-038480-1)
This is a revision of an excellent and thorough text which presents Roman history in a more detailed fashion than Starr.
* Henry Boren, Roman Society . 2nd ed. (ISBN: 0-669-17801-2)
This book concentrates on the social and economic history of Rome.
* Plutarch, Makers of Rome. (ISBN: 0-14-044158-1)
Plutarch wrote a series of biographies, called the Parallel Lives, of famous Greeks and Romans in matched pairs in order to compare their virtues and faults. Plutarch had access to many materials no longer extant, so is an invaluable source of information. His concentration on individuals helps make people come alive. The biographical approach has some limits and problems, however, by tending to make the individual more important than he actually was in the context of his age. Plutarch himself, in writing moral biographies, tended to focus on elements that demonstrated the inherent goodness or evil of the individual. He doesn't make up or alter facts, but he is quite capable of collapsing events to concentrate on his themes and instruct his readers on human behavior. Plutarch, like all writers is a product of his background and time. For Plutarch, this means sympathy for authoritarian government as long as it is improving the morality of the people.
* Suetonius, Lives of the Twelve Caesars. (ISBN: 0140449213)
A contemporary of Plutarch, Suetonius wrote this set of lives of Julius Caesar and the first eleven Emperors ("Caesar" was used as an imperial title). Unlike Plutarch, Suetonius was not writing balanced biographies designed to show moral issues. He was presenting a mixture of historical material interspersed with a large amount of gossip, scandal, and intrigue drawn from anti-imperial sources, mainly memoirs of senators who longed for a return of the Republic. Suetonius is often accused of being uncritical in his inclusion of material from dubious sources. The result can be entertaining, but certainly the lives are biased information. On the other hand, Suetonius gives us considerable important insight into the personalities of those who ruled Rome during the first century AD.
* Livy, The War with Hannibal (ISBN: 014044145X)
This is an account of the most difficult war in the history of the Roman Republic by Rome's greatest historian. Livy wrote during the reign of Augustus (about 200 years after these events) and wrote from a Roman patriotic viewpoint. This is one of our best sources for information about Hannibal and the war Rome almost lost. It may acquaint you with the way Romans wrote history and viewed themselves.
* Eusebius, The History of the Church (ISBN: 0-14-044535-8)
Eusebius was a bishop during the reign of Constantine who wrote a history of Christianity up to his own time. This is valuable for getting the Christian attitude toward history and a fascinating study of the views of a fourth century Christian author. Some of the material is fanciful, but all is from the Christian point of view.