Help is needed here.

Okay so like I'm in ITT and for homework I got to make a pic using photoshope. I know what I want to make but don't know how to go about it. I want to make a space scene in a glass orb, (like the pic only well space) Then I want a hand holding the orb but the top of the orb to be cracked.
I have no clue what the background would be, More then likely just a black screen, Though I would like to put something on there that would be kinda cool but don't know how to do the reflections and what not. Stups though sitting next to me is being a dick :< and won't help.
But. CAN ANYONE HELP ME!!!

What, you whant someone to do you homework for you?

No I want some help. I'm so lost as to how to go about things. I see it in my head but when I google how to do it I can't find anything that looks right. I was hoping that someone could show me how to go about making it.

http://www.corbisimages.com/images/6...2-20312851.jpg

And maybe some background like this.
http://files.myopera.com/phamlythanh...apers%2026.jpg

Just throwing out ideas :P

The second pic I would like in the orb and the way the orb is cracked in the first one is perfect.