Would can be used whenever there is something that you will do on your wish, without anyone forcing you. Should has to be used when there is a pressure of having it done. Ex: 1. I would like to do my homework when I am not busy. 2. I should do my homework right now, or else I will fail the exam. Hope it was a little clearer than before. ^_^

"Would" is the past tense of "Will". Would is basically used in a negative fashion. Because it is past tense, it kind of means the opportunity has already passed so you can't do it anymore. Ex: "I would do it if I could but I can't." Will is used for a positive meaning, you can do it. Ex. "I will do it because I can." "Should" is the past tense of "Shall." Should isn't negative like Would is. Should kind of gives off the sense you still can do it. Ex: "I should go to school." Shall, is the exact same as Will, but less common. Ex: "I shall go to school." ***Should is used when something is more recommended when Would is something used when you can freely do which ever option. Hope this helps you understand^^