Al, This is a very good question because measuring and marking accurately is the key to most successful projects.
The work that I do covers the full range from small toy making to building construction and the measuring tools that I use reflect that. Below is a list, but before the list a couple of points:
• I have metric equivalents of almost all these tools but will not include them in the list.-Carpenter's Square (LV 60N48.01)
• The majority of my measuring tools come from Lee Valley and, for those, I have put the catalogue number in brackets after the item.
-Rafter Layout Square –Stanley
-3 inch Steel Engineer’s Square (LV 24N07.03)
-4 inch Steel Engineer’s Square (LV 24N07.04)
-6 inch Folding Square -45, 90, 135 degrees -Nobex Quatro 200 (LV 01N02.01)
-12 inch Folding Square -45, 90, 135 degrees -Nobex Quatro 400 (LV 01N02.03)
-16 inch Steel Ruler –no name
-Ruler Stop for the 16 ruler –Veritas (LV 05N68.01)
-40 inch Steel Ruler -no name
-25 foot measuring tape –Stanley Fat Max
-100 foot measuring tape –no name
-10 inch Sliding bevel –Veritas (LV 05N44.01)
-Bevel Setter -Veritas (LV 05N66.01)
-Protractor –no name
-Compass –no name
-Blind Man Digital Calipers -Veritas (LV 88N62.57)
-Marking Gauge –brass, 3 in 1 (LV 05N65.01)
-Striking Knife - Veritas (LV 05U07.10)
-several sharp pencils
-Set-up Blocks – Veritas (LV 05N58.10)
There are other associated tools such as levels, winding sticks, straight edges, and shims that I have not included in the list.