Take a few photos, then just write the details about the model of the console on the sale page. You can then upload the images, with the best one being used for the main picture that people see while searching.
Then, set the payment methods you want to accept. Usually, people prefer Paypal, which is instantaneous and goes directly into your Paypal account, linked to your bank account. If you don't use Paypal, then you can also request a cheque for payment I believe.
Set a reserve price, and then open the item for bidding. I would recommend a reserve of around 180-200, as they are not sold any longer and are sought-after thanks to the backwards compatability allowing them to run PS2 games.
Be honest with the item condition, when posting on EBay. I noticed you said the item is unboxed, which I assume means it has been used quite regularly. Make sure you specify this when selling.