Man greeting Man - Men usually shake hands when greeting one another.  Handshakes are usually on the firmer side and don't linger that much.  If you are greeting someone you are very close to then a hug is acceptable.  

Woman greeting Woman- At a first meeting, women generally shake hands.  Kisses on the cheeks are common if you know the person very well.  If you are greeting someone you are very close to then a hug is acceptable.  

Man greeting Woman-   At a first meeting a regular handshake will do.  Kisses on the cheeks are common if you know the person very well.