You wanted to know about Dosas so here it is:
There are a number of recipes of Dosas using different ingredients in each one of them.
This is the standard recipe served in restaurants:
Sada Dosa or Plain Dosa
1 cup split black gram
3 cup rice
1 cup cooked rice*
1 tsp salt
1/2 fenugreek seeds
Wash and soak split black gram, fenugreek seeds and rice together for 6 - 7 hours. Grind it finely. Add the cooked rice and a little water and grind it again. Add salt. The batter should be of pouring consistency. Keep it aside in a warm place for 8 - 10 hours till the batter rises like the bread dough.You need to use a container where the batter takes half the space so the dosa batter does not overflow when fermented.
Heat a non-stick griddle until hot. Pour 2 tbsp of batter and with swift strokes, spread the batter evenly on the griddle before it gets cooked and becomes difficult to spread. Put a tsp of oil all around the dosa and let it cook at a medium heat till golden and crisp. Remove and fold it in half. Serve hot with coconut chutney and sambar.
* This is one of tips which are rarely mentioned in the cookbooks but adding this makes the dosa light and crisp.
I knew nothing about Dosas until you asked so I cannot claim to be that clever - the recipe comes from Vandana who lives in Southern India.