Set up iCloud - how? How? HOW?

I bought an iPhone 4 from a cash converter site.

I want to set up iCloud. I have a laptop.

I've downloaded iCloud onto my laptop.

I have no idea what to do next to set up an iCloud account.

Can you give me a step by step as to how to set up an account?

Assume I'm a complete idiot.

Which version of iOS is the phone using? YOu may need to update the version of iOS and then you will have iCloud available in the Settings…

http://support.apple.com/.../kb/HT4623