Install CentOS 6.3 on Lenovo 3000 N1000

First, go to CentOS websites and click the "Downloads" menu, choose "Mirrors"  and check the "Mirror List".  Pick one and follow the link to download 6.3 ISOs.

2nd,  make a CD or DVD by writing the 6.3 ISOs into a blank disk.

3rd,  insert the disk into the CD ROM, and reboot your computer.  Goes into BIOS by pressing "DEL" or "F2" key or whatever your screen reminded you.

4th,  choose boot from CD.  Your computer will start booting from CentOS.
Just follow the instructions to install CentOS on your computer. Better have a dryrun to make sure important devices(for example,  Ethernet Card) are supported by CentOS.

Above steps look easy, but do some homework before you get started.

1. Can your computer install CentOS?  Does CentOS have all the drivers for your computer?
2. Do you want to erase all the data on the hard disk and install CentOS solely  or you want to do dual boot? This will affect which partition you want to put your CentOS or whether you want to override your MBR.

Better have a check list and ask around before you start in case you lost all your important data. Search online resources whenever you are not sure.  Google or Bing or Wiki will help you for sure.  

I won't post all the screens here since most of those steps can be achieved by searching online. 

After installation, make sure the network is working :)