Hi Morine
We're happy to have you with :)
Yedda for me is more than anything a network of people. A rather sheltered space where each and every one of us can be both somebody's answer and somebody's question. You could be just the person to answer my particular question, and I can be this person for someone else.
In a nutshell, good questions are those which are interesting and relevant and meaningful to you. Good answers are those that shed light.
Having re-read my response I think I'm taking this to a philosophical place you may not want to go, so as simple as I can:
A good question includes relevant information, is clear, precise and hopefully evokes thought and reflection.
A good answer is informative, coherent and supplies the information or the reference where the information can be obtained.