In this second posting see how popular the candidates are:
those contesting are
Le Pen 2012
Polls and analysis of polls can viewed on these sites.
Sondages en France
Harris interactive includes discussion of use of internet and voting intentions.
TNS –sofres polls and analysis.
CEVIPOL has current and historic reports on voting intentions.
Comparison of polls on Nouvelobs
Sciences Po coverage of the election includes expert analysis and polls.