Freud's work can be divided in four major periods*:
1. The exploration of neurosis, from the inception of practice (1886) until the "Studies on Hysteria" -1895.
2. Self-analysis - 1895-1899.
3. Id psychology, in which was
elaborated the first system of psychoanalytic psychology - 1900-1914.
4. Ego psychology, involving a considerable extension and elaboration of the earlier ideas, lasting from 1914 until 1939.
Several articles and resources on this site cover all these periods.
Related to his work see also:
*Reuben Fine, "A History of Psychoanalysis", Columbia University Press.