Got a new digital camera and not sure of the symbols?

 This is the macro symbol.  It means that you are taking pictures close to your lens.  That is usually small objects close up.  Most point and shoots have this symbol.  Check your manual, to understand your camera's limitations in this setting.  Use this to shoot flowers, butterflies and anything you want a very close up picture.  The depth of field will be more limited as you are closer and holding the camera steady may require a faster shutter speed, or very steady stance.

A  refers to Aperture Mode:  Aperture is the width the lens opens when the shutter is released.   The guide numbers are also called F-Stop, the  focal ratio which technically is a the focal length divided by the aperture.  What it means simply is that on most SLR"s including digital SLR's your fstop is the number on the lens or on your display represented in numbers such as 1.4, 2, 22, etc.  It is a representation of how wide the shutter opens the aperture when the shutter is released and therefore how much light enters the camera.  The smaller the number the bigger the opening the more light that comes in.  The larger the number the smaller the opening and less light comes in.  Shooting inside, the f stop would be in the low numbers such as 1.4 or 1.8  on a bright sunny day it would be higher such as 22.   Some basic issues with fstop is that the smaller the number the less depth of field you will have in your photo's the larger the number the more depth of field you will have.
So when the camera is on A the priority is the aperture, size the shutter opens the lens or fstop, is set and  the adjustment point then becomes the shutter speed.  So if you have your camera set on A the aperture stays static and the shutter speed is adjusted to compensate for different lighting.  This allows you some level of control on the sharpness or lack of sharpness of the images in the back ground of your pictures.