Welcome to Trulia and thank you for your question!
If your listing is already on Trulia, here's how you can submit the open house information to us:
Find the "detail page" for the listing (you can do that just by searching for the address on Trulia). In the top right corner of the detail page, you'll see a "Tools" section. In the Tools section, there's a link that says "Submit open house times". Click this link and fill in the relevant date and time info.
If your listing is not already on Trulia, access the link below to submit the listing information, along with any open house dates and times, to us.
Please let us know if you encounter any difficulties with either of these processes or if you have any other questions.