I am trying to take the dash out of my 68 charger. There is some rust up underneath the dash and a bunch of crud from 40 years of life on the road. Is this an easy job? Does anyone know of a book or an article somewhere that describes how to take everything apart?

Are you looking to take the complete frame/dash assembly out or just the instrument cluster and misc. items?

If you're looking to take the dash frame out, you'll need to remove the windshield...

I want to take everything out so I guess I will have to remove the windshield. Is this something that can be done at home or do I need a windshield guy?

I have been able to remove windshields myself using a couple different sharp utility knifes to cut the gasket out. Take your time removing the trim as well. If you have reservations hire a glass guy. You will find 5 or 6 screws under the bottom of windshield that hold the top of dash. There is also a screw at each end that fastens to the lower dash to kick panel area.
You will also want to remove or drop the steering column as well. I like to remove it completely to do a good job. Hope this helps!

I need to get the windshield changed on my civic so maybe I will get the same guy to pop the glass out of the charger. Steering column???? What is the difficulty level or dropping it?

No big deal take the steering column out.
There is a roll pin that you have to drive out that is where the steering shaft connects to the steering gear. Look for the round hole about 1/8" about an inch or two before the end of the steering shaft. The pin is pressed into this hole. The pin only drives out one way so if you have trouble try the opposite direction. There are 3 bolts?? that attach column to underside of dash. Lay on your back and you will find them. Then 4 bolts that attach mounting plate to floor where shaft passes through floor to outside. That's it... Will take an hour two the first time. After that it is no big deal once you figure out how to get out the roll pin.