A good starting point is to use the symbols in the Generic Components library - here you'll find many of the components that we use in our own symbols, with front, side and rear views already in place. It's easier to edit something that already exists than to create everything from scratch.Yes, you can type in exact values. Check out the Help system and read up on Command Line Entry. For example, with a rectangle selected you just type in 17, 3.5 to set its dimensions as 17 wide by 3.5 high. This assumes you have set your units (Options | Preferences) to Inches Only.