Book excerpt: Dylan Landis has an inside track with the decorating pros. Elegant and Easy Rooms will tell you their opinions on everything from how to arrange furniture in comfortable and imaginative ways to how to choose a color to create a certain mood or period (in the 1940's a particular shade of yellow was the most popular). The chapters include: Paint and Color, Walls, Windows, Problem Rooms--Great Solutions, Home Furnishings, The Art of Display, and Telling Details. There will also be an incredibly useful and valuable appendix listing all the best mail order resources for everyone's decorating needs. It will be illustrated with charming, elegant black and white drawings that will further entice you to upgrade your decor.