Congratulations on the purchase of your home.
I believe you should start by claiming the property. Under the main picture scroll over the button "Edit home facts". Then click on "Claim this home" Click on your name and it will probably prompt you through a series of steps to register and be able to change the pictures.
If this doesn't work visit the help site at: http://www.trulia.com/help/ask/
Here you can ask a website representative to guide you through the process.
At your home's price range I would strongly suggest to do a laundry list of low cost maintenance tasks before you post your property up online. This will ensure the right first impression, attention and ultimately top dollar for your property. Let me know if you would like to work with me as I'am sure we can sell or lease your home for a very attractive price.
Equitable Co. Realtors
5600 S.W. 135 Av. Suite. 206
Miami, FL 33183