Hard to add much to great advice so far --- whiteblaze really is "the" place for AT prep.

Do you anticipate an early March or late March start in 2014? If early March then you might make sure to get some experience at walking in/on snow and ice beforehand and tune your early gear to be able to handle somewhat cold and windy conditions during the day and temps that can get into the teens at night.
I'm not sure how fast that gets on average "better" as you approach later March, and of course conditions can vary a lot year to year.

I hesitate to mention this, as I'm really not trying to shamelessly advertise (!), but I wrote a book aimed at folks pretty much like you --- the "planning" type of person out to do their first thru-hike, wanting to get the most out of their planning time and money. Hopefully the moderators will make clear if I'm crossing a line by mentioning it, but assuming that's okay the book (in Amazon Kindle format only) is here: http://www.amazon.com/dp/B00AJ68TVW