The best way to get a homes value is to contact a few agents and have them prepare you a free Comparative Market Analysis (CMA). It is free and it will reflect the most recent sales. The agents can also look and see what properties are in contingent and pending status meaning they are in escrow. Often times the agent can contact those listing agents as well to find out a ballpark value as to where those properties will close. This helps predict which direction the neighborhood values are moving in.
I recommend using an agent to get you the homes value as well as if you want to do a home search. A ton of homes on Zillow and other similar sites are listed as available for sale but are not. In fact there are some that have close 6 months ago that are still listed as available. You can get set up on a direct feed from the MLS through your agent and they will send you homes that only match your criteria the second they become available. This data remains first hand data straight from the source and this data is up to date because agents will get fined by NAR if their data is left inaccurate. Zillow and other similar sites are not held to this standard.
Most consumers are unaware of all of these factors. To top it all off the seller pays the agents commissions so if you are a buyer you get professional representation and accurate/timely data for free (sorry seller's but you pay the fees).
I hope this is helpful.
Get you FREE Comparative Market Analysis (CMA) from Robert Adams at Sankey Real Estate HERE.