When you first install Windows you are asked to create a user account. You can create a Microsoft account or a local account. I recommend using a Microsoft account because settings are stored in the cloud and it automatically creates space on Microsoft OneDrive, which is cloud-based storage.
You have the option of creating a local account, which does not use cloud-based storage, nor does it store settings online.
The following web page describes how to create both local and Microsoft accounts.
http://windows.microsoft.com/en-us/windows/create-user-account
A major flaw in older versions of windows, prior to Windows 8, is that accounts, by default, had administrator rights. This left the operating system wide open to attack from malware and hackers.
Best Practice
Create a separate Windows account for each person using your system.
Modern versions of Windows have corrected that mistake. The first account created, the one Windows asks about during the installation process, is an administrator account. User accounts that you create are, by default, not created with administrator privileges. This fixed the largest, most gaping problem with Windows security.
Every person who uses your computer should have their own Windows account. In addition, a guest account should be created for those instances when someone stops by unexpectedly and needs to use your computer.
Best Practice
During your normal day-to-day activities, do not log into the Administrator account. Use a user account instead.
To create accounts, select the User Accounts control panel. This will display a screen similar to the following:
Click the Manage another account link.
At the bottom of the window that is displayed, you will see a link titled Add a new user in PC settings. Click that to add a new user. You can create either a Microsoft account or a local account from the utility. Normally it is recommended to use Microsoft accounts.
The process for creating and managing accounts is described on this page:
http://windows.microsoft.com/en-us/windows-8/microsoft-account-tutorial
To allow for unexpected guests who need access to a computer, I recommend creating a guest account. You can use the built-in guest account for convenience, or, better still, you can create an account with a fake name, make it a normal user account, and change the password each time you need it.
To use the built-in guest account, bring up the User Accounts control panel as described above. Click the Manage another account link to display the screen shown below.
Click the Guest icon to display the following window.
Turn on the guest account and your visitors can log in using the username guest without a password.
You should only enable the guest account when needed and disable as soon as it is no longer required.