Hello! I looked at the specifications of your MacBook, and unfortunately, you won't be able to install OS X 10.8 Mountain Lion (the latest version of OS X) because your device is unsupported. The newest version you can install is OS X 10.7 Lion (the next-to-latest version of OS X). However, this requires the previous version, OS X 10.6 Snow Leopard. Thankfully, OS X 10.6 Snow Leopard can be installed as an upgrade from either OS X 10.4 Tiger or OS X 10.5 Leopard. Please note, though, that you will need to purchase the Mac Box Set and Single Use License of 10.6 Snow Leopard in order to install it on your MacBook. You can procure a copy of this software through the online Apple Store (please click here to visit the exact page from where you can purchase it). Alternatively, you could search eBay or Amazon.com for discounted copies of the same software. You might want to try clicking here, here or here for a start. After installing OS X 10.6 Snow Leopard by inserting the installation disk into the disk drive and running the installer, I would recommend conducting a software update, so that your operating system will be updated from 10.6.0 or 10.6.3 (depending on whether you purchase an original or updated installation disk) to 10.6.8 (the latest update to OS X 10.6 Snow Leopard). After this has been done, you will be able to update straight away to OS X 10.8 Mountain Lion by purchasing and downloading the installer through the Mac App Store, while bypassing the update to OS X 10.7 Lion, if you would like to do so. I wish you the best of luck. I hope this helped! 🙂