Newbie Questions and Errors

[DLX]

Hello all

you be happy I have a list
I have been clicking about this can be dangerous  :-[
When I use screenshot program it can cut a bit of screen I like to copy but when I save the floating window goes blank and then stops responding. So I use xkill to close as don't always shut down.

So I thought I try update LL see if that would fix screenshot program got this error.

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/...slation-en  Hash Sum mismatch
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dist...slation-en  Hash Sum mismatch
E: Some index files failed to download. They have been ignored, or old ones used instead.

Tried to uninstall but not in list to.

Next one I have change colour of Panel took me a bit of time to find how was looking under desktop setting. I would like to change the clock number to white as they are black and can't see then now also Menu is black texts. I have looked at window manger and setting but hoe long to I keep clicking around. Can someone pint me in right direction please.

Last one I would like to have my Window to snap to side of screen like in Win 7. I looked at Google found talking about Aero Snap.

Is there something I can tick on in LL to get this or if I follow step will this work in LL as it's for Ubuntu or is there a better way ?
[pre]compizconfig wmctrl[/pre]http://www.omgubuntu.co.uk/2009/11/aero-snap-ubuntu-linux

Thanks.