For this sequence, begin with a warmup of things like shoulder rolls, cat/cow, and downward dog, and progress to Sun Salutations. Do at least 4 Sun Salutations to get the blood flowing and the heart rate up. Bear in mind, 4 is the minimum here-do as many as 12 to make sure that you are properly warm. This series will not only challenge your balance but will greatly stretch the legs, so do a series of leg stretches before attempting this series. If I have my knees straight, and you are able to balance but unable to straighten your knee, that is a great starting point. Gradually build up flexibility and don't push your body past its capacity. I recommend beginning with the first video, the so called "intro" to balancing, before moving on to the advanced second video. One difference between the two series is that in the intro, each pose is done on both legs before moving on to the next pose; whilst in the second video an entire series of poses is done on one leg, then the same series is repeated on the opposite side. Please watch the video first to make sure this is something you want to attempt. After these series, continue on to floor work like backbends or abdominal work (http://yogabymelissa.blogspot.com/2010/04/yoga-for-abs.html), or conclude with some cooling stretches.
Basic Balancing Sequence:
Advanced Balancing Sequence: