Not usually. Most of the workbooks that I use are self-contained.
But I will put those linked cells and ranges on another sheet to be out of the
way.
Depending on what you're using (Worksheets/Userforms, controls from the Forms
toolbar or controls from the Control toolbox toolbar), things are different.
If you rightclick on one of the controls from the forms toolbar, you can assign
a linked cell and an Input Range (under Format control).
If you go into design mode (an icon on the control toolbox toolbar) and then
rightclick|properties, you can assign the LinkedCell and ListFillRange.
And what's returned is different from the Forms toolbar and controltoolbox
toolbar controls, too.
The Forms stuff returns an index into the inputrange. The control toolbox
toolbar returns the actual value.
My opinion is that the Forms stuff is easier to work with, but the
controltoolbox toolbar stuff offers a lot more power (to do neater stuff).
Play around by rightclicking and looking.