Check out the Practical Machinist website. It has a wealth of information about virtually everything machinery and metalworking related. I have been documenting the rebuild of our toolroom lathe on the site and the pictures and discussion are very informative. Post #127 of the thread details and discusses optical alignment of the lathe spindle axis to the ways of the machine. Found a picture of the bedliner we applied to the work areas of the lathe. Turned out great.