Sort a list of lists

if i have a list of lists like this one: (the one i have is obviously much larger but this is the idea):
new = [['dog',2],['cat',5],['bye',1]]
...
how can i sort it according to the numbers on the second column, i.e., new[0][1]=2....?
i.e., new.sort should become: new.sort(sthg) = [['bye',1],['dog',2],['cat',5]]

How can i access all the numbers in the second column together like it was a vector?
i.e., new[sthg][sthg] = [2,5,1]

How would you sort it alphabetically up/down?
i.e., alphabetically up: new.sort should become: new.sort(sthg) = [['bye',1],['cat',5],['dog',2]]
i.e., alphabetically down: new.sort should become: new.sort(sthg) = [['dog',2],['cat',5],['bye',1]]


Another basic question:
if i have a list L, L[:] means what?????

I am a newbie in python...

Thanks for the help,

Daniel