For a more complete history behind the typographic grid, I’d suggest the following:
• Wikipedia’s entry on the canons of page construction: http://bkaprt.com/rwd2/68/
• The New Typography by Jan Tschichold (Second Edition, University of California Press, 2006): http://bkaprt.com/rwd2/69/
• Grid Systems in Graphic Design by Josef Müller-Brockmann (Verlag Niggli AG): http://bkaprt.com/rwd2/70/
In looking at how grids apply specifically to web design, I’d suggest:
• Ordering Disorder: Grid Principles for Web Design by Khoi Vinh (New Riders Press, 2010): http://bkaprt.com/rwd2/71/
• A Practical Guide to Designing Grid Systems for the Web by Mark Boulton (Five Simple Steps, forthcoming): http://bkaprt.com/rwd2/72/
• Mark Boulton’s blog entry, ...