I ordered the American Sour Beer book, but haven't read it yet.
I've made saisons but not sour beer, using WL saison blends which include regular yeast, brett and bacteria, so I'm just getting into it myself. My saisons weren't really sour at all, but I didn't really let them age more than 6 months before they were all consumed.
From the information I've gathered, there is a difference between Brett character and beer sourness. You need the bacteria lactobacillus or pediococcus to get the sour in sour beer. Pedio should be used with Brett because the pedio with put off some diacetyl and other compounds the brett will take care of. Lacto has a "softer" sourness and can be added to a beer that has already been fermented.
One rule of thumb I've heard is you should make a successful gallon of sour beer before you try 5 gallons, and 5 gallons before your try 10 and so on, don't just jump in and try a 59 gallon wooden barrel.
At the same time you'll be building up your "house culture" of lacto/pedio and brett.
I'm starting my sour "program" with a flanders red Rodenbach clone that will take at least 18 months and two different brews that will be blended. I'm also starting a 100% brett fermentation beer and another one that uses a primary fermented with lager yeast and then a lacto addition. I'm waiting to get the book though before I launch any of this.
Here's a great podcast about sour beer:
http://podbay.fm/show/920652546