I like this guide. I am not experienced enought with CSS work to comment on it in detail. I am also a big fan of Scalable and Modular Architecture for CSS (SMACSS) approach advocated by Jonathon Snooks.
Now just have to get the dark matter/mort developers on board to understand CSS is not just adding !important or letting a program parse your .Net or Java code into div, id, class spaghetti.
Bits I liked from Nicolas' guide.
Presentation-Specific styles are those that only alter the visual design of the element, but don't change its dimensions or position in a meaningful way.
Nice point on Bootstrap
Bootstrap is awesome for quickly hacking together a presentation layer. This is particularly neat when putting together back-end, admin panelsy views that won't be customer-facing.
It's not so hot when developing customer-facing products because they end up looking the same, mostly. My other issue with CSS frameworks is that they get very much in the way of the namespacing I suggest, which is at the core of the style guide
This amused
If you are reading this, I salute you. You're almost as boring as I am. I'm more boring because I actually wrote the damn thing. It's not a contest, though.