Okay the process is pretty simple and fun. First enlist someone to help you measure. Measure the length and width of the room in a straight line. Also measure the height of the walls from floor to ceiling. Multiply the length of each wall by the height of the wall. This will be your square footage for the walls. Next add up all the areas doors (if using a different color for the doors), windows, and fireplaces) by multiplying the length x width of each item. Add each of those square footages together. Now subtract the square footage of the doors, windows, and fireplace (if any) from your first calculation for the walls. After you subtract for those items you are not going to paint, you end up with your final square footage. In order to find out how much the paint will spread divide the final square footage by 350. A gallon typically covers 350 square feet, for rough surfaces divide by 300. For your convenience, Benjamin Moore and Behr have paint calculators if you run into trouble. Use the same process for trim and doors. Only paint in a well ventilated area with the windows open on warm days so that you can air out the room without being cold. Use frog tape instead of the blue painters tape, it works better. If you are pregnant, don’t take any chances painting or being around any chemicals for that matter.