Creatine is one of the key energy systems in the body.
The body maintains a set amount in the system based on your diet.
Supplementing simply raises the amount that the body maintains.
When this increases, in addition to all the other benefits...
(Read this to see what we know about the benefits
http://www.discussbodybuilding.com/Creatine_Reviewing_what_we_know/m_295206/tm.htm)
The amount of water retained IN MUSCLE along with the increased Creatine increases.
Muscle IS about 75% water.
Putting more water in your muscle, often referred to as volumizing muscle, increases their ability to GROW.
how soon do u think untill i see some VISIBLE changes
What you will notice in about 4-8 weeks, depending on your diet and training, is that you can train more intensely.
You recover faster between sets, allowing you to train with greater vigor.
It is possible to see a gain of 3-10 pounds in that time. Most being water but some may be muscle as well.
If you read that link I gave above you see that creatine does some great things for the training athlete and their body.