Generally you'll need to Clone your system if you want to put a newer or bigger hard drive in your PC or Laptop without losing all your programs and setting. Cloning will copy everything from your existing drive to the new one so it will boot up just as it did before it was replaced and have all your programs ready to run and set up how you like it, but be a different/bigger/newer drive. You don't have to do this, you could just put the new disk in and boot from your OS disk and start from scratch again. Or on a PC you could add a second disk as a slave and still boot from the original.

So you have a Laptop and a new disk, the first thing you need is an enclosure (about £7) that you can run the new disk in.  Some Hard Drive come with a Clone program on them if not download "HDClone free addition" or something like that (you can't just copy files across it won't work). Plug in your new drive/enclosure, the laptop should recognise it but don't worry if it doesn't, run the clone software and it will ask you the drive you wish to copy and the drive you wish to copy it to (it should find your new drive). Then it let it run.
When it's finished, take the drive out of the enclosure and swap it with the original one. Switch on and it should boot straight up as usual.

Once your happy if you want you could put the old drive in the enclosure and use it as an external back up drive or whatever. I'd leave it for a while until your sure everything works correctly.