a brief history of time is an excellent book and its basically written for laymen so its pretty easy to understand
i think before the big bang there was another universe and that its an infinite cycle of compression and decompression in something much much larger than even the universe
if you look at a molecule its basically spherical in shape and you'd think its so small nothing can be smaller, but then theres the atom
i think its the same with the universe only bigger
planets are roughly spherical, stars black holes, etc etc etc.
i think the universe is only a tiny (in relation) part of something even larger and the thing that it helps to make up is a small part of something again even larger
its just my personal opinion though
im an atheist so by definition i find the thought of a "creator" illogical
because theres the obvious question who created the creator?
with this theory there neednt be a beginning nor end as its a cycle
in the big bang all matter begins compacted and then hits a certain point (read about it, its too complicated to explain on a net forum and im no expert) and explodes/begins to expand
with the uncertainty principle all matter is becoming more disorganized as there are more disorganized states for it to be in than organized, to use the analogy stephen hawking did in the mentioned book, picture a jigsaw puzzle in a box assembled correctly, now shake the box, the chances of it landing again in an organized fashion are billions to one, so logically it will become disorganized
now when all matter is disorganized in the universe and becomes somewhat uniform it begins to contract because the forces of gravity pull it together
then it gets down to a point that all matter is as compressed as it can get and then boom
the boom part is explained in the book also
its a good read
....i typed way too much, this is what happens late at night when i dont have any weed
http://en.wikipedia.org/wiki/Big_Bounce