Need ideas where to start for 68 resto

[GMKiev68]

My son is 16 and he wants to restore my wife's grandfathers 68 Chevy. It is a gold/white LWB that has been out of comission for about 15 years. It has been out of the weather/sun under an RV shelter, and at first glance appears to be in good condition. It has always been garage kept in some way so the paint is pretty nice and the interior is immaculate. Of course the tires are shot, but beyond that it is rust free with perfect glass, and I think it is a good place to start. He has a little knowledge, and I can do pretty much everything short of getting into the engine block.

Here are a few questions I have:
Where can I find the best VIN decoder, for engine, tranny, etc.?
What is the best type of shop manual I can buy?
Other than changing all fluids, belts, and battery, what do I need to do just to get it to crank?
We just want to get it roadworthy, with a budget of about $200 a month. Is that something we could do over the next two years?

Thanks for your time and responses. All of my previous experience has been on 60's model Mustangs, so you see how misguided I am!
David