If the exact words of the speaker are given, the verb say must always be used.  Say cannot be used with an indirect object, but must be followed instead by a phrase with to.  

    She said to the clerk, "Do you have a good warm coat?"

    Then she said, "How much is it?"

The verb tell is often followed immediately by an indirect object without to.  When the exact words of the speaker are not given, you say something, but you tell someone something.  

    She said (that) the movie was good.

    She told them (that) the movies was good.

    Please tell me his name.

Note:  The conjunction "that" is often omitted in conversation.

The verb tell is used in the following special expressions:

Tell the truth        Tell a lie               Tell about something        

Tell the time        Tell fortunes        Tell a story

Click here to quiz yourself on the use of say & tell

Contributed by: Paul de la Chesnaye         pdelache@swbell.net