any CAD softwear is way better. Auto CADD is super easy to use and works pretty well. you can get AutoCAD light. it will do it for you. you can only really do 2d drawings in acad light, but it is free and easy to get....
you don't need plans that are so exact either do it by eye sight using a tape measure and pen to mark your shapes and a ruler, taht's all i used and my rail is as good as it gets