Selecting - how to differentiate "elements"? In the attached test_bag.blend file, the bag has several parts: front, back, base, etc. How does one select an individual "part" of the bag without selecting others?
For example, select only the front or back or interior part.

Further, I would appreciate a link to, or in depth tutorial of, selecting/selections; -- beyond the basic tutorials on utube, et.al.
TIA

https://dl.dropboxusercontent.com/u/3504807/test_bag.blend1
There are two ways in edit mode (&#8633; Tab):


Press L while hovering the mouse over the part of the bag you want to select. This will select all the geometry which is connected to the part under your cursor.
Select some geometry (e.g. with  RMB), then press &#9096; CtrlL. This will select all the geometry which is connected to the existing selection.


If you want to separate the parts into separate objects, then press P> Loose parts in edit mode. This will separate disconnected parts of the object into their own objects.