Trulia does not sell houses, it's a real estate site allowing Realtors to post their listings and provide real estate information and answers to consumers.
The best way to purchase a house is to interview a few Realtors (preferably by Referral), or you can look for Trulia contributors from your area (check on Member Search for the town you are interested in), read thru their answers and if you like their answers, call to set appointment and interview them to be your agent.
If all things fail, you still need recommendation, I can refer you to our Relocation manager who can help you find an agent to work with you.
But the best way is to go with referrals from your friends and relatives. The agent can help you put a sound offer together.