Thanks to all who responded, including Dave MacEwan, David Barnes, Rebecca Cooper, Justin Kraemer, Wendy Geary, Chris Bruce, Joseph Howell, and Denis Roose, who pretty much all suggested the same thing.  As expected, I was simply in the wrong place.  Below is the original question followed by Rebecca's nicely typed step by step process.  Thanks again....this list continues to be an invaluable resource!

Original Question:
I have a street file with the field "name".  The name field is populated with street names and many "UNNAMED" values.  I want to display all the streets, but only label the streets where [NAME]<>'UNNAMED'.

In AV8.1, under layer properties, labels tab>Text String>Expression> Expression Properties it appears I can define an expression (in VB or JavaScript parser) to control what gets labeled.  I can't seem to put any expression together to achieve what I want...which seems conceptually pretty simple.  Perhaps I'm in the wrong place altogether....the AV8 help file is rather brief on the "Expression Properties" topic.

Rebecca's response:
Your expression is correct, but you are just entering it in the wrong
location. The Text String Expression button is for changing the display of
the labels. For example, you can display labels from two fields on different
lines by entering, [NAME] & vbnewline & [TYPE] as the expression. If you
want to create a label subset of your table, create a class.

1.  In the Labels tab, select 'Define classes of features and label each
class differently' from the Method dropdown box. Additional buttons will
appear in the dialog.

2.  With 'Default' shown as the Class, uncheck the 'Label Features in this
class'.

3.  Select the Add.. button and type a name for your new class (hit OK)

4.  Select the SQL Query button to define your class. In the SQL query
dialog box, enter your desired expression that will select the desired set
of features for this class.

    [NAME]<>'UNNAMED'

5.  Click the verify button to test the query expression, and click OK to
close the dialog.

6.  In the Text String Frame, select the field that defines the label text.

7.  Use the Symbol button to define your text symbology, the Label Styles
button to select a symbol (if you want to use a road shield) and the 'other
buttons' to set scale and label placement properties.

8.  Click the OK button, then label your streets.

Have fun.