So here you go - straight from my google search to your computer.
A monogram is a motif made by overlapping or combining two or more letters or other graphemes to form one symbol. Monograms are often made by combining the initials of an individual or a company, used as recognizable symbols or logos. Obvious right? Well here is the thing I did not know that there is an order to things depending on what you are monogramming.
A traditional 3-letter monogram has the initial of the individual's last name (surname) set larger, or with some special treatment in the center, while the first name initial appears to the left of it and the middle name initial appears to the right of it. For example, if the individual's name is Mary Ann Jones, and Jones is the surname, then the arrangement of letters would be thus: MJA, with the surname initial set larger in the center, the M for Mary to the left and the A for Ann to the right.
Married or engaged couples may use two-letter monograms of their entwined initials, for example on wedding invitations. Married couples may also create three-letter monograms incorporating the initial of their shared surname. For example, the monogram MJA might be used for Michael and Alice Jones.However, monogramming etiquette for the married couple varies according to the item being monogrammed. Linens, for example, typically list the woman's given initial first, followed by the couple's shared surname initial and then the man's given initial (AJM). (Text Wiki)
So do you monogram? I love it but don't do it as often as I should. I think that they are great on gifts, maybe a note to add to my gift giving list this year.