Jackie McDonnell (Yogi) and Matt Signore (Worldwide) have put together comprehensive planning guides that include gear suggestions, desert & snow strategies, logistical data and town details.
In addition, Yogi’s Books does great deals on map sets for both trails. Professional quality, double sided productions of Jonathan Ley’s CDT maps (I used them during my 2012 thru hike) and Half Mile’s excellent PCT equivalents, are available for less than you would pay at any reputable print store.
On a personal note, over the past couple of years I’ve run into both Yogi and Worldwide at various hiker events. You would be hard pressed to find too many people more passionate about the Triple Crown trails and the hiking community in general. Between the two of them they have logged more than 45,000 miles on US long distance pathways over the past two decades.
Yogi’s Books are made by hikers for hikers. Highly recommended.