Here is the glyph for Mercury: a little person wearing a hat, like a delivery boy.
Mercury rules the signs 
Gemini and 
Virgo.
Ancient astrologers looked in the sky and saw a strange little light that followed the Sun very closely. He would show up just after sundown in the evenings for a couple of months, then disappear! Then he would show up in the mornings just before sunrise for a couple of months, then he was gone again! This was Mercury, messenger of the Gods, who got a reputation for going hither and thither and being something of a prankster.
The keywords to keep in mind for Mercury are:
The Mind: Day-to-day communications and thought processes
Short travels and trips
Intelligence
Capacity for learning
Information
Details
Mercury’s sign shows how we communicate: do you communicate quickly (Aries), slowly (Taurus)? Forcefully (Leo), softly (Pisces)? Methodically (Virgo), or off the top of your head (Sagittarius)?
The people and things in your life ruled by Mercury are Siblings, Pets, and Machines.
Mercury rules the hands, lungs, and nervous system.
Molly Cliborne
1 · D Brammer · 3 December 2007
All this is interesting, But Is Any Of It Real? Or Just A Way To Make Money And/Or Feel Special?
2 · Molly · 4 December 2007
Study it, and you’ll Find Out.
3 · Gregory · 31 January 2009
What does my Mercury in Taurus in the 8th House mean?
4 · Peggy · 9 November 2009
loved your answer to D Brammer! wish more people would study astrology then all of the misunderstandings would be cleared up.
5 · Molly · 9 November 2009
Yeah, but why study when it is so much easier just to make blanket judgments of other people.