Check your Mac’s serial number without turning the laptop upside down or contorting yourself to see behind an iMac screen or… well, you get the idea (also, no squinting at tiny numbers).
Choose About This Mac from the Apple menu, and click under the Mac OS X title, directly on the Version 10.x.x text that says what OS version you’re using. You’ll get a “Build number,” which is more specific info about the software. Click again, and you’ll get your Mac’s serial number.
