Well you should begin customizing it to suit your style. Here are a few advices that I recommend(does not apply to servers)

You should set up how people(or you) log into the computer. I suggest inputting a password to prevent pesky people from accessing your important files. To do so open up the start menu-->control panel--> User accounts. Then you will see something similar to this

Here you can change your picture logon, change your name that the computer recognizes you by, and input your password.
This is something for those portable computers like the NetBook and the Laptop. By also going to the control panel-->Power options you can select the power scheme of your portable friend
Here you can set your power options, if set correctly, you can save battery juice often when traveling.
If you go over to the advanced tab...
You should be able to set your laptop/netbook to do nothing/sleep/shutoff when you close the lid. The sky is your limit!
The most important item in the control panel if you ask me. Everyone needs a good antivirus, and constant updates to keep your computer safe from the evil internet...

Always keep your firewall on, it can save you the hassle of those hackers hijacking your data goods. Even though I don't have the option set up, I highly suggest to keep Automatic Updating at a green light(automatically download and install updates). As I mentioned, everyone needs a Virus Protection. In this case my antivirus is the ever popular Avira Antivirus which i suggest because it's free and does a damn well good job keeping those viruses away. For more antiviruses check the external links page, or for you lazy people click HERE.