So I have a cinder block block that is about 4 feet high.in which I will be putting a framed 8' wall. I will be using a 2x6 sill plate PT. How much space do I leave for the sheathing. It's an exterior wall. Also once the sill.plate is down, can I put.my studs on it or so I need an additional plate.
It's recommended (and possibly required by building code) to add a sill seal below your sill plate. These are usually inexpensive rolls of foam, and serve to protect the sill plate from rot. The sill plate also needs to be properly anchored to the foundation, generally every 4ft is required. As far as a second sill plate, this isn't required.
Single bottom plate, double top plate. Wall sheathing is typically 7/16" thick.
Current code in my area requires 2" rigid foam insulation on the exterior of the block wall. Some builders have been using 2x8 walls so they can overhang it over the foundation 1-9/16" so the face of the wall sheathing is flush with the face of the foam. I think it's silly, but that's what they're doing.