There isn't a kissing tutorial as such but creating a kissing scene just requires the poses or motions to be created in the Motion Editor or purchased in a motion pack.
If you haven't already, go through the Getting Started section of the Motion Editor help guide which gives an excellent start to creating your own motion files.
If you would prefer you can purchase ready made kissing motions and poses and there are a number of them in the Wedding Planner Theme Pack. (see image below and click to go to page)
Peter EdwardsForum Moderator
iClone Daily Blog