Newbie here too I'm few weeks away from my first tour. I built my own bike though.

My advice is to read as much as you can here and on Crazy Guy on a Bike. Tons and tons of touring knowledge. But don't limit yourself to the Touring forum. I found that Utility Cycling and Car Free forums have some relevant information too, and the Commuting forum

Other good sources of knowledge:

http://kenkifer.com/bikepages/ (Sadly Ken was killed several years ago by a drunk driver)
http://www.biketouringtips.com/

Touring journals, besides CGOAB, reading touring journals gives you a lot of information and insight from actual tourers on the road:

http://pathlesspedaled.com/
http://www.downtheroad.org/
http://www.ridingthespine.com/
http://www.cycling-adventurer.net/ (BF member)
http://www.machka.net/ (BF member)

Here is my journal that documents my preparations:

http://www.crazyguyonabike.com/doc/AdamsFirstTour