Since our "alternate route" for the Northern Pass project is to bury the lines, what are the differences, advantages, and disadvantages of undergound v. overhead transmission? Bob Craven has found three articles that will walk you through the basics, and I'll add a fourth.
3. Article 3 is a comprehensive overview of many aspects of electric power transmission. It covers the many state and federal regulatory agencies that have authority for electrical power transmission, many of which have overlapping jurisdictions. (Warning: 3 MB file.)
4. The last, actually a website, discusses a "new breed of high-capacity, long-haul electricity transmission that’s ideal for remotely located power sources, including renewables." (Disclosure: this is a commercial site.)