We started the cleaning and prep to stain the slab yesterday.  We were unable to finish so we got up early and were back at it at 7 this morning.  We finished at 8:45 a.m.  After mixing the stain in a sprayer we began staining and finished two and a half hours later.  We are now waiting for the stain to dry so we can do a second application. 
This ended up being a labor intensive project.  We still have much more to do before we are finished.  Our slab contractor told us that we saved $6000.00 doing this ourselves.  I think that the toughest thing about it was that Janice and I had never done this before.  We got a crash course, bought the supplies, and jumped right in. 
Today and tomorrow we have to wash the dry stain dust off the slab and squeegee it off.  It will lighten the color to the color that we saw in the store (it had better!).
We had to wait 28 days to stain the slab (time required by all the stain manufacturers).  It was a long 28 days.