I'm glad to hear that you found out how to delete a post. For those who may have the same question, please follow the steps below.
1. Make sure your profile indicates that you are a property manager or landlord. To update that, access http://www.trulia.com/myprofile/, select 'Edit Profile' and update your personal information accordingly.
2. Access the My Listings section of your account: http://www.trulia.com/account/listings/
3. Click on the 'For Rent' tab and then select the 'Edit Listing' option for the property in question.
4. Select the option to delete the listing
I hope this helps.