'nice to meet you' 

What I always use is 'nice/good to meet you too'. Are there better ways to response?

'how are you'

I usually reply 'Good', 'I'm good', 'Great'. I'd like to know what you usually use.

Another thing is what to say after someone replied 'Good'. It's a little bit embarrassed to just stop the conversation here. This happens everyday when I go to office and greet my colleagues. I want to be kind but sometimes I just don't know what to say.