Which version of Windows are you using? I'm assuming that you are a small business and it's Windows since you tagged it under PC, so apologies if I made the wrong assumption.
Assuming these are new PCs running Windows 8, you will need to setup a new user account. If you don't want them to be able to install any apps from the Windows Store, it will need to be a local account. So...
1. Sign in as an admin.
2. On Windows 8 start screen, type in "add user."
3. Click on "Settings" then "give other users access to this computer."
4. On the resulting "Users" screen, under "Other Users click on "add a user."
5. The resulting screen will offer to setup a Microsoft account. If you want to make it a local account, click on "sign in without a Microsoft account" on the bottom of the screen, then confirm that you wish to make a local account.
6. Enter the login info (name & password + hint) on the next screen, then click OK.
7. You can enable the "family account" setting if you want to further restrict access and get a report of activity for the day.
This obviously isn't the way to go if you are a big business, but if you just have one laptop that you want a number of employees to share, this is probably the easiest way.