Make certain that insulation and vapor barriers are properly installed, and that the temperature in the building is above 32 degrees Fahrenheit. Check the studs and roof trusses for level and plumb --- straight up and down.
Add strapping where needed, using 1-by-4 or 2-by-4 studs between the wall studs and ceiling joists or roofing trusses, to provide a solid surface for the metal screws that will hold the liner panels in place. Liner panels should run parallel to the wall studs, which are placed every 16 inches apart. A standard liner panel is 36 inches wide, so you may need extra vertical strapping between the studs.
Install wood blocking where needed around all openings.
Screw in the base trim along the bottom of the wall. If the wall ends in a corner, install a piece of cove trim in the corner. If it is a straight wall, screw up a piece of J-trim. Cut these trim pieces to fit with a utility knife or tin snips. Check trim for level and plumb.
Begin inserting panels, starting in the corner. Insert completely into the base trim and the cove or J-trim. Leave a 1/4-inch gap at the end to allow for expansion and contraction. Cut to fit, if necessary, using a radial arm saw. Screw in place with metal screws, sinking the screws at least 1 inch into the stud. Place screws no farther apart than 24 inches, and at least 4 inches from the ends of the panel. Check for plumb.
Put the next panel up, making certain it is interlocked along the entire length of the first panel, and is inserted completely into the base trim. Screw in place and continue on around walls, adding cove trim at each corner.
Add supporting 1-by-4s or 2-by-4s where needed for any suspended lighting or other fixtures.
Install any trim before setting panels into place on the ceiling.
Install panels on the ceiling in the same manner as the wall panels.
Apply silicone caulk to any exposed corners, fixtures and holes.