Insert into a table , values for this table will be fetching from another table

Transact-SQL
1

new to sql..plz help

2 
INSERT INTO ATable
	(col1, col2, col3)
SELECT
	colA, colB, colC
FROM
	AnotherTable
-- WHERE 
--   some filtering condition if you have any
3

dennis, when posting it is a good idea to state your problem again in the body of the post.
Also examples of data and table layouts are helpful. That said @JamesK did a good job of showing the general overview.