Prepare the room before starting the removal process by shutting off the power to the room and covering the floor with plastic and dropcloths.
Soak a section of the wall with very warm water containing a heaping tablespoon of baking soda or one cup of vinegar. Use a sponge or a spray bottle to apply the mixture. Allow the mixture to set on the wall for five minutes. Remove the glue by scrubbing in a circular motion. Scrape stubborn sections with a plastic scraper, using the sponge afterward to wipe off. Keep a bucket of clean water handy to rinse the sponge.
Use four tablespoons of fabric softener or a generous squirt of dish-washing liquid in a bucket of very warm water if either of the above two mixtures does not remove the glue. Use the sponge and the plastic scraper. Rinse well.
Remove wallpaper glue that is very stubborn with a mixture of trisodium phosphate mixed in warm water. Follow the directions for proper amount to use. Use caution with this product, it is very strong. Wear safety glasses and gloves. Rinse the wall as each section is cleaned.
Sand any remaining glue that becomes evident after the walls dry. Use a medium, 150 to 180 grit sandpaper, sanding in a circular motion. Wipe the walls with clean water to remove sanding dust.
Choose the proper type of paint for the room(s) being painted. Choose a semi-gloss for kitchens, bathrooms and other high usage rooms, since semi-gloss paint washes well. Use flat paint in bedrooms and other areas that will not require washing as often. Flat paint is difficult to wash, but there are brands of flat paint on the market that are marked washable.
Determine the square footage of the area being painted. Multiply the perimeter of the room by the height. Divide the figure by the coverage area listed on the paint container; this is also the amount of primer required. Double if planning for two coats, and always purchase a little extra paint to have available for touch-ups.
Repair all nail holes with spackle, allow it to dry and sand with fine-grit sandpaper. Remove switch and outlet covers, replacing screws in the outlets and switches to avoid losing them. Mask all trim and baseboards with painter's tape. Wrap doorknobs and any other items that need to kept paint-free with aluminum foil. Lay dropcloths to protect flooring and furniture.
Prime walls that wallpaper glue has been removed from to seal them. Allow the primer to dry and visually inspect the walls for any areas of wallpaper glue that you missed. Spot sand these areas and re-apply primer. Any glue remaining on the walls may show up as blotches or flat areas under the new paint.
Roll the paint on the walls diagonally and then vertically to assure complete coverage. Allow the walls to dry, check the paint container for drying time. Apply the second coat, if needed, using the same procedure.