I assume you are FSBO. You can go to postlets.com and make a listing. It will upload to Trulia, Zillow, AOL, Yahoo and several others all in one entry. Have as many pictures as you can. Good luck with it.
Try Postlets.com, they syndicate directly to Trulia. Trulia is an agent only platform at this time so all listings need to be listed through a broker. If you are an agent then you can also manually input it as well.
If you are a for sale by owner the post is not allowed, you can however try blogging about the property; if and when you do list with an agent, he/she can post it for you, ask; or consider any flat fee realty company that feeds into the site.