Cropping irregular shapes - Photoshop Elements 6.0

Cropping irregular shapes
Can someone out there help with what I'm sure is a simple task for
those who know Photo Shop -obviously, by my asking the question, I do
not.
I have a newspaper article that was scanned and then given to me.  I want
to manipulate in Photo Shop prior to including it in a slide show.
The article headline is 5 columns wide.  The desired article beneath
is 3 columns wide with the other two columns filed with advertisements
and other undesirable material.  I am wanting to "crop out" or
eliminate those adjoining "undesirable" columns.  I cannot do it by
using the standard cropping tool - at least with my knowledge.

Help, please, I know this should be an easy task for those in the know
- unfortunately I am not such a person.