Refer to the hardware vendors site for more information
RAM: The bigger RAM, the better. The minimum required is 512MB. Check the corresponding RAM for your specific distro – others might require a bigger RAM allocation.
Sound Card, Video Card, Printer: Make sure that these are compatible with Linux. Refer to the hardware vendor’s site for more information.
Next, make space for Linux.
If you opt to install Linux without removing your current OS, note that your existing operating system uses the whole hard drive. This means that Linux and your current OS needs to share the hard drive so that the two operating systems can co-exist. You will need to partition and divide the hard drive. If you choose to take this route, make sure to take a backup of your system because there is a risk of wiping out the data on the drive.
To facilitate partitioning, you can get hard drive partitioning products that run on Windows, or you can use a GUI called QTParted that comes with most Linux distributions. Some distributions (like openSUSE or Xandros Desktop) can reduce Windows partition and automatically create partitions for Linux. In case your distribution of choice offers this feature, you will no longer need a partitioning tool.
Here are the partitioning steps for Ubuntu: