what are the processes in finding the main idea and where can you find the main idea?

Question

There are several articles here which discuss the "main idea" of something.

http://www.google.com/search?q=find+main+idea&rls=com.microsoft:en-us:IE-SearchBox&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7SUNA

It all depends, though -- main idea of what? A paragraph? An essay? A story? A poem? A novel? What?

Answer 1

I first that

Answer 2

I second that

Answer 3

I third that

Answer 4

I fourth that

Answer 5

I number five that