Not just about campaigns...

"Ultimate Campaigns" by Jason Bulmahn and others,
published and distributed by Paizo Publishing.
ISBN = 978-1-60125-498-6.  PZO # 1125.

Quick Look-see:

01) Character Background
02) Downtime
03) Campaign Systems
04) Kingdoms and War
05) Index
06) OGL

Detailed Look:

Part 01 - Character Background.  Everything from creating a background for your character, to Story Feats.  My favorite part in this chapter is the random background generator.

Part 02 - Downtime.  What =is= your character doing when they are not being currently played?  My favorite part in this chapter is the buildings and organizations section.

Part 03 - Campaign Systems. Covers a bunch of ideas including everything from your character's alignment to younger characters.  My favorite part in this chapter is the Magic Item Creator.

Part 04 - Kingdoms and War.  The two sub-sections are: Kingdom Building and Mass Combat.  My favorite part in this chapter is the whole section on mass combat.

Part 05 - Index.  A decent two page index to the book.

Part 06 - OGL.  The usual Open Gaming Licences.

My major unusual "complaint" about this book is that it spends 195 pages of its 254 pages for character development.  Although characters are a vital, nay, indispensable, part of any campaign, DM's that pick up this book were probably looking for less about character development, and more about campaign development.  This info probably should have been in an "Ultimate Characters" book. 

"Character Development" is the area where GM's should consider putting things that link the character to their campaign world.  This should become an idea factory for things that can crop up during your campaign that affect a single character while providing adventures for all your other characters.

"Downtime" includes stuff like repairing and maintaining equipment, and resting to name two.  It even starts by going into building a single building, hiring managers to run your business while you are adventuring, and some ideas on random events that can occur in the city.

The "Campaign Systems" section has a lot that I don't consider part of campaign systems, as it is about single campaign development.  This is where I would like to have had more about building a world.  One of the better parts of this section is the "Companions" part.  There's also a really good section about purposely losing skills that you don't want anymore, and retraining that now empty slot for another skill, with ideas for all character classes. 

The "Kingdoms and War" section includes a really good part about building kingdoms, although it seems to me to be geared towards PC use.  But, it still is a really good idea factory for GM kingdom development.  But, for sheer usefulness to GM's, you can't beat the mass combat section.  There's a lot of info about building a single building and what they cost.  Buried in the K&W section is a great part about special abilities. 

Even including all that, though, this is another hardcover book from Paizo that should almost be indispensable for GM's, and close to indispensable for players.  One of my higher recommendations.