After you get your extent, to select the features in a layer named 'Stands' intersecting the extent rectangle, do this:
mxd = arcpy.mapping.MapDocument('CURRENT')
df = mxd.activeDataFrame
ext = df.extent
lyrs = arcpy.mapping.ListLayers(mxd, "Stands", df)
if lyrs:
lyr = lyrs[0]
else:
return
a = arcpy.Array()
a.add(ext.lowerLeft)
a.add(ext.lowerRight)
a.add(ext.upperRight)
a.add(ext.upperLeft)
a.add(ext.lowerLeft)
thepoly = arcpy.Polygon(a)
arcpy.SelectLayerByLocation_management('Stands', 'Intersect', thepoly, 0, 'New_Selection')
You can read more about SelectLayerByLocation in the online help. But it sounds like you really don't want to select features as much as grab some attributes. If that is the case, then I'd set up a search cursor, curse through the records, and if the shape of a feature intersects the poly we made above, grab the attributes of interest. good luck,Mike