I would like to wipe the SSD of my MacBook Air and do a fresh install of Yosemite. There is a lot of junk on my MBA currently which has slowed down the machine and would like to start over with a clean OS install.
What is the best way to go about this? Note that I am a noob when it comes to OSX installs on Macs. It will be my first time.
As above, create a bootable USB pen of the latest OS X, which is currently 10.10.2. You can download it from the App Store.
Once that is done, shutdown the unit. Insert your USB pen, and hold down ALT (OPTION) whilst restarting the computer. You will be asked which install you want to boot into. Your original OS, the USB installer or Recovery. Click on the USB Installer. Allow it to boot up, this takes a good five minutes or so.
From there you will need to open Disk Utility, and wipe the SSD. Once wiped, close Disk Utility and follow the prompts onscreen.
In about 15 minutes, you should have a new install of Yosemite.
And, don't forget to back up all your data before doing any of this!
Good luck.