I knew I was in trouble the first minute of the first day of class for an engineering physics course. Well, I felt the same way the first time I went into a paint store to pick out the paint for my new house. Hundreds of paints, dozens of implements and shelves of special additives and cleaners.

Here's what you need to know before selecting paint. Stick with a national manufacturer and buy one of its higher grades.

Make sure to buy enough paint to finish the job. If you have to leave a half-finished wall to run and get more paint, the overlap will show, even if the color is a perfect match. A gallon of paint typically covers 400 to 450 sq. ft. Estimate the number of square feet you'll be painting by measuring the total footage around the perimeter of the room and multiplying by the ceiling height in feet. Don't subtract for windows, doors or other openings unless they're enormous. Ceiling areas are easily determined just by calculating the width times the depth of the room. Two or 3 qts. of wall paint cost nearly the same as a gallon, so round up to the next gallon if you need a fraction greater than one-half.

An average room's worth of trim including baseboards and a door or two will need a quart each of primer and one of semigloss trim paint. Have the store shake the cans for you, and stir them every time you paint.