crew sleeping!!! hehe and a quick mining question

I'm having fun with the sandbox mode on Alpha 0.5.3.  Everything was going great, until all work on my new ship ceased.  Little did I know, my entire crew was asleep on the mining station! lol  Lazy bums!!

On a serious note though, how exactly does mining work?  I found on the map several resource locations, and I ticked the "+" button to increase the resource "amount".  I also assigned miners.  Is this all I need to do?  I was told I was low on "critical resources".

Thanks! Love the game so far!