Book reviews can be found in Journals (print and online). Here are some titles to help you get started:
Australian Journal of French Studies
PQ1 .A8 (1965-2014)
Canadian Modern Language Review 
PB1 .C3t 1944-2009
Diacritics
PN80 .D5 (1971-1978) (Microfilm Stauffer)
Online (1971-present)
Forum for Modern Language Studies
PN2 .F74 (1965 - 2004)
Online (1996-present)
French Review
Online (1927-2013)
French Studies
PQ1 .F85 (1947-2003)
Online (1996- present)
Modern Language Notes (MLN)
PB1 .M59 (1886-2000)
Online (1886-1961)
Online from 1962-
La nouvelle revue française
AP20 .N85 (1953-present)
Revue d'histoire littéraire de la France
PQ2 .R4 from 1894 - 2008 (some breaks)
Year's Work in Modern Language Studies
REF PB6 .M68 (1930-2009) (reference collection and compact shelving)
Online 1930-1994 (exception 1940-1949)
