Transfering from original hard disk to a new one

I bought a new internal 1TB hard disk for my MBP. I haven't done anything on MBP yet, so I am not afraid of losing any files but I am concerned about Mac OS X.

How can I transfer the original hard disk to a new internal one? And if I do that, will I have to install Mac OS X all over again or will it be already installed. And will it work the same, considering it is on other hard disk? Will it be any slower or anything?

Easiest and best way is pop the new drive in an external case, connect up, format and select GUID option and run SuperDuper to clone the hard drive. Then pop the new drive in the MB and existing drive into external case for use as backup drive.

The other option is to make a Time Machine backup on the hard drive.
What I did was to make my 1 TB externat hard drive into 2 partitions with disk utility and used one of those partitions as a time machine back for my internal hard drive. And you do not have to re-install OS X. You can just boot your MBP from the OS X dvd and from the menu par select time machine and it'll put the last Time Machine backup on your internal Hard drive. Like a direct copy.

Super Duper is another option as mentioned above to do the same. Some prefer Time Machine as I do. Others prefer Super Duper. Both in this instance do the exact same thing giving the exact same results.

Thank you both, you were very helpful.

Considering that I am not worried about my files being lost because I don't have any cuz it's a new MBP, could I just place the new hard disk and install the Mac OS X with the installation cd? Would then the Mac OS X be the same as when i bought the computer, just on 1TB disk?

Yep, same thing.