"bisous" - it is more used by children and women (I never used this term, it is seems to me little akward).
It is also often used with "gros", "gros bisous"
"bises" - it is less affective, and more neutral
one can say "allez ! bises, on se voit demain"
"bise" in singular - "ils se sont fait la bise" - they say hello to each other (by kissing, french tradition)