I think what this forum needs is for mrb and Norcal to co-author a STICKY that is a comprehensive discussion of installing a basic 100 amp (er..... 90 amp) feed to a garage.
One which would give recommended wire sizes, both copper and aluminum and why AL is quite OK and why you cannot use a 100 amp breaker to supply 2-2-2-4, but why 2-2-2-4 is probably the best choice for most people, and why you need a panel that is larger than one ever thinks they need and why a disconnect is needed at the detached building and why 2-2-2-4 that originates inside the house or other building needs to be in conduit inside, and also the pros and cons of using Romex vs EMT or other conduit and THHN wire, and why ROMEX cannot be used in wet locations (and define what a wet location is)......................... and on and on.
Yes, this is alot of material, but I think it can be boiled down to eight or ten different posts contained in one sticky thread, with code references and possibly links to some of the better previous discussions. AND some good books to reference.
After about the um-teenth identical question from a new Cessna 150 owner, this is what I finally had to do to make things go better on the forum I moderate.
Let only mrb and Norcal write or modify the thread and if one of the other gurus on here has something new, different or relative to add, PM it to one of those two and let them edit and add it in.
How to books just really don't work for alot of things people ask on here. Indeed, if you just don't know what you are doing, you need to keep your hands out of it, but if you are willing to carefully learn, have someone knowledgeable to help you (who might learn something from all of this too) then this would be a good STARTING PLACE to help people plan their electric service to their shop.
Make sure it starts off with a huge disclaimer, a couple of paragraphs about how this is not a how to, but rather, an assist with planning and to provide education to insure that whoever does the work for you, does it correctly.
Again, on the Cessna 150 forum I moderate, there are some how to things that are beyond the legal limit for a non-licensed (mechanic license, known as an Airframe and Powerplant license) aircraft owner, but many licensed mechanics don't know what they are doing either when it comes to these small birds, and our FAQ's help the owner keep his mechanic on the straight and narrow, and save them money too, by not chasing the wrong gremlin. We've kept mechanics from going around the world troubleshooting a problem, on more than one occasion by providing the owner with good solid info that the mechanic was not aware of and would have never gleaned from a manual.
Well, enough, and hope something comes of this. I'm sure the moderators would be willing to make the thread sticky and locked, most discussion forums have a few of these and they are worth the time spend creating them.
Charles