I do not recommend determining property values with online services, either Zillow, Trulia, or any other service or source that does not include three things:
1. Knowledge of your local market trends
2. Knoweldge of your personal situation (for example, when you need to sell, how much you need to net, etc.)
3. Knowledge of your property
The best way to find our what your home would sell for is to ask three Realtors for their opinion. There are generally three prices at which a home will sell:
1. Wholesale - what an invester might pay, usually 10-12 % below retail
2. Retail - what a willing, able , and knowledgeable buyer will pay and to which the seller will agree.
3. Your price - based on your circumstances, needs, and goals.
I do think that you can learn a great deal from Zillow and Trulia. Go to the STATS section in your zip code and you can look at the market activity. What you need are a few things not present:
The market trend for homes like yours, and the current competition. That's why a CMA on it's own, or simply "market data" can actually be more dangerous than help.
If you need a sharp Realtor feel free to let me know and I can refer one to you.
You can reach out to me on Facebook or email me at firstname.lastname@example.org. I also have a Ewing People page on Facebook that you can search for where I post market updates, absorption rates, and active inventory. It will give you a better picture of the current environment.