The first quilting instruction book I bought (loooong time ago) used 1/2" seams throughout the book. As the others have said, this is okay for basic blocks (I also use this for some kids quilts). The best thing is to learn the 1/4" seam--all patterns today use this so you wouldn't have to convert them to accomodate a larger seam. Also doesn't work with triangles, OBW's, very small blocks.
Practice, practice, practice LOL!!