Babies and children are amazingly ready to develop and learn. We need not fear that without our encouragement, they would cease to develop. They are entirely devoted to the task of growing and learning from the moment they are born. A good key thought to remember is that a child grows through different stages, and each stage has its appropriate learning and developmental focus, and with each one comes a new stage of consciousness. Some things vary from child to child in order and intensity, but generally, there are archetypal steps a child follows at each age. Being aware of where the child is in these stages and recognizing what she is developing at this stage is immensely helpful, especially in giving insight to what the baby's experience is. The less we interfere with a child's natural development, (for example by sitting them, standing them or helping them walk before they are able to on their own) the more we allow them to strengthen their bodies and develop a subtle sense of balance that is right for their specific body. We allow them the time to learn to move on their own, not rushing them through stages that have lifelong consequences for the development of the body and coordination. The less we interfere, the better. (For a wonderful description of each stage, see the Pikler article on Stages, as well as the link to Living With Children below.)
When we observe the child's abilities, we are able to present objects and activities she is ready for and would benefit from, and are less likely to push her. We are also less likely to overwhelm her with too many sense impressions and are likely to give her more time for what she is working on. It can also be interesting to participate in a child's development by observing what they are learning or teaching themselves through repetition. It makes much more sense than showing them too early something that will take them much longer to understand or do than if it is introduced at the right time.
A simple example: when a child learns to go down stairs, we know most children first go down backwards, facing the staircase. Because we can observe it quite easily, we know she is now learning about going down the stairs. Most would not try to force a child to go down facing the front until she feels steady enough to do so in her own time. We respect where the child is, knowing she is in the first stage of learning to go down, facing the stairs, without pressuring her to move on to the following stage before she is ready.
When it comes to less obvious physical stages, however, or stages of consciousness such as those that pertain to the child's intelligence, and mental capacities, we often tend to lose sight of what stage the child is in, and push concepts and expectations onto her that are much ahead of where she is in her development or where her present interest lies. By observing the child and seeing what she does, we are able to gage what she is developing and working on of her own accord. Respecting each stage reduces stress on the child, allows her to learn better and allows her to develop a joy for learning independently. It's also important, as much as possible, to let the child focus on her task and not interrupt her. One can always ask oneself if an interruption is really necessary, or if we can give the child time to conclude her task.
I highly recommend reading the article Non-verbal Education-A Necessity in Development Stages by Michaela Glockler (see below) where she gives an in depth description of stages of childhood.
See Stages of development
Toys and the importance of play
How to make decisions
The negative effects of media
The Plug-in Drug- Parenting before TV - Marie Winn
Development of movement - stages - Emmi Pikler
Clothes for he baby and small child - zur Linden
Living with Children http://www.creativelivingwithchildren.com
An incredible, not to miss resource for all aspects of becoming a parent, raising children and understanding their development with consciousness, creativity and courage by Susan Liang.
From Research Institute for Waldorf Education
http://www.waldorfresearchinstitute.org/research-bulletin-articles/ Here is the article:
Non-Verbal Education- A Necessity in Development Stages - Michaela Glockler
 Pikler, Emmi. Friedliche Babys, zufriedene Mütter. Pädagogische Ratschläge einer Kinderärztin. Herder Verlag, Freiburg, Germany 2000