The asanas in Light on Yoga are almost all ordered in different groups: standing poses, sitting poses, forward bends, inversions, twists, arm balances and back bends. In the different groups they are ordered regarding their difficulty. So if you practice from asana 1 to asana 200 you will end up with practicing asanas from difficulty one* to sixty* (according to Mr. Iyengar's Light on Yoga) which I guess is too much.

In the asana courses at the end of the book they are ordered in the way you should practice them. So start with these practice sequences.

If you are interested you can also see a very good sequencing article at

http://www.bradpriddy.com/yoga/sequen.htm.