install linux in a computer with existing windows system

I have bought a computer recently which have windows vista installed already. My computer is x86_64 Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz. The total size of hardrive is near 300 G. I tried to install linux also in the machine. Here is my procedure.

1) use a partition software to adjust the size of windows system, and leave the remaining space unallocated to the new installation

2) put linux installation cd in the computer and restart the computer and choose to install the linux system

3) make the new partition after checking the whole hard drive(sda). In my case, I

designate 20G for ext3 filing system for root
designate 4G for swap
designate the remaining to "ext3 filing system" for /home

5) continue the installation and finish it

6) restart the computer, both windows and linux system should appear for your choice.

Use "fdisk -l" to check the harddrive information.