Trying to learn a* (again)

For years I have not been able to understand how the a* pathfinding thing works. A couple of weeks ago I memorized the g h and f variables. F is the combined g and h values. G is the movement cost and H is the estimated movement cost. Memorizing these got me a little further in understanding the a* algorithm. But I still have a long way to go to fully understand it.

For instance. How do you expand the search area. I can not understand this yet.

I wish there were more articles on a* for people who do not understand the algorithm. I have under 10 different source codes of a* but what the codes do is still a mystery.

Update :
I learned that the h cost is the distance to the end position. And that g is the distance from the start position. I think that anyways after studying the examples I found. Still I am still stuck on how to find that path itself. I have no idea on how to do that. I plan to study sourcecode and I hope to learn something on that.