The young child can pay attention to any one activity only for a short time particularly if it is challenging. Instructional tapes and most software with music are distracting, and weak listening skills paired with short attention span make audiotapes and most videotapes non-effective. Parents put a lot of faith in computers but software by itself also cannot teach your child to read. Unfortunately, most commercial reading programs emphasize flash and entertainment over structure and content. These programs entertain and engage the child but fail at actually teaching them to read.
Most children can begin at age four.
You can begin teaching the sounds of letters at about four years. Simple reading instructions can be started about the same time. By five the pace of new learning and reading fluency can increase dramatically. Most children can learn to read at the second-grade level, by age six. Of course not, but you may help significantly.