Can We Bless Hashem?

What is the idea behind the korbanos-sacrifices? Why was King David the prime example of someone who knew how to conciliate with Hashem? 

How does a wise beggar get a full meal from his host? 

How does a wise woman ask a favor of a friend? 

How does a farm worker get a bonus from his boss? 

In what way is Dovid Hamelech compared to the farm worker? 

What is the lesson of R' Yishmael Kohen Gadol (the High Priest) who came into the Holy of Holies and Hashem asked a blessing of him? 

How can a human being bless Hashem? 

Can we do the same?