I really like this simple, yet useful tool which the Facebook agency SkandNet has released today. It helps you through the process of producing the main images needed for the Facebook page and Facebook timeline.
I went through the whole process and I found it pretty straight-forward. Upload an image, choose auto-resize or manual crop, maybe a background color and - tata: a zip folder with your images in good quality and perfect size is created, which your download and then just up-load on to your Facebook page.
Here is the link to the tool: www.skandnet.com/timeline