How do we know when we have received revelation?

My goal this year has been to study the Doctrine and Covenants to help me better learn about Revelation.  I have been studying from the free BYU Inpendent Study class on the Doctrine and Covenants.  This is a great supplement for me since all my church classes are in Spanish and my comprehension is probably only around 20%.  I now really appreciate doctrine. I feel the spirit in classes sometimes, but hearing of the doctrine is what opens the mind and then the Holy Ghost confirms or testifies of the doctrine we have come to understand.  I have found myself craving doctrine and this online class has been a great source of spiritual nourishment.

I just read a quote that I think has been the best description of how the Holy Ghost works in regards to personal revelation.

"We often question how to know when we have received revelation. President Harold B. Lee described this very well: "When there come to you things that your mind does not know, when you have a sudden thought that comes to your mind, if you will learn to give heed to these things that come from the Lord, you will learn to walk by the spirit of revelation" (Harold B. Lee, in Conference Report, Mexico City Area Conference 1972, p. 49)."