Caesar wrote a book about his campaigns in Gaul (the title is usually translated as Commentaries on the Gallic War). It was intended to promote his victories (and defend the legitimacy of his campaign) with the Roman public, to check the influence of his numerous elite critics. It's a good read, but you have to keep in mind that the purpose of the book. It's also taught very frequently in Latin classes as it is relatively easy to read. There are a number of affordable editions in print; the Oxford World's Classic edition translated by Carolyn Hammond is a good one.

Caesar was a prolific author who gave to the western Cannon many idioms (veni, vidi, vici—I came,I saw, I conquered—for example). Perhaps his most famous collection is a running narrative of his military conquests in Gaul in order to send back to Rome and thus influence public opinion there. This narrative is usually titled in english The Gallic Wars (Comenterii de Bello Gallico).

Caesar had real literary talent, and he describes first hand some of the most important moments in the late republic. Very much worth the read.