http://www.amazon.com/Gettysburg-Invasion-Allen-C-Guelzo/dp/0307594084
Do NOT get me started on the title. It's inaccurate.
Sterling Price led an invasion of Union states well over a year later, penetrating a great deal farther into MO and KS than Lee did into MD and PA. Wasn't turned decisively back till the Battle of Westport in October of 1864.
To be fair, the CSA claimed MO as one of their states, while they didn't claim MD. But both PA and KS were indisputably Union and free states.
Rant off. :)
To address your actual question, good book. Lots of diagrams.
I have read a number of books about this battle and campaign, but had not previously realized how many times Lee almost broke the Union Army. Or how disorganized the fighting was on both sides. Very little effective coordinating was done by either Lee or Meade. The battle played out as it did mostly due to decisions made at corps and even division level.
In re staff work and coordination:
It was, as you fairly point out, fairly wretched on both sides. However, perhaps we shouldn't hold these people to more modern standards. This was among the very first times in history such large armies were massed against each other over such wide areas, were able to use railroads, and had fairly accurate long-range artillery and infantry weapons. Put the controls were not yet developed. The General Staff concept had not really been invented yet. Also, coordination still depended upon nothing more advanced than the heliograph and telegraph lines of limited reliability between corps headquarters and Washington and Richmond. In actual combat, ,most of the orders were still transmitted by semaphore when possible, mounted couriers, and runners.
In fact, I'd wager that the General Staff concept was born because of the War of Secession.