Man greeting Man - Men shake hands when greeting one another and maintain direct eye contact.  A relatively firm handshake is the way to go.  Light hugs are common between good friends and family. 

Woman greeting Woman- At a first meeting, a light handshake will suffice.  Light hugs are common between good friends and family.  

Greetings between Men &  Women-   At a first meeting a regular handshake will do.  Light hugs are common between good friends and family.

Note: In French-speaking areas, men and women will often give each other a kiss or kisses when greeting and departing.  Same goes for women greeting women.