There is a website with local information called http://www.localism.com. Just search for Santa Monica. As far as schools go, we use a website that rates schools called http://www.greatschools.com. However, Santa Monica is one of the tri-cities School Districts along with Beverly Hills and Culver City..considered some of the best!
If you would like to see what is for sale in the area,I have free access to the MLS on my website below (no obligation)
If you can afford to live in Santa Monica, you're pretty well equipped to pick and choose (to a fair extent) where you want to live on the Westside and schools shouldn't be an issue for you. On the other hand, Santa Monica has only 2 homes in the whole city for less than around $800k right now. Of the remaining 126 properties for sale only 16 are below a million dollars, with an average asking price for all homes on the market of well over 2 million dollars. I haven't been in the 2 bargain homes ($550k & $699k.) They could both be tear downs, but both are relatively close to the beach and the less expensive one is on a regular sized lot and actually shows a photo of the interior on the listing. I'm not suggesting that either of these properties are viable, or finaceable, or that you should necessarily even consider them. I am suggesting that you may have to get a little creative and keep an eye towards the future, depending on your circumstances.
As for the rest of the westside south of Pico, you can typically find a lot of homes for between $600k and $850k though deals will occasionally pop up for $500k to $600k. Mar Vista (90066,) Palms (the western part of 90034,) part of west L.A. (western 90064,) much of Culver City (90230 & 90232,) and surprisingly parts of Venice (90291) fall into this category. Also, if you're willing to go a little farther east, really nice homes can be had for a bit less.
For homes in Los Angeles under $500k, you may want to look at a blog that I recently posted here on Trulia titled: The Most Affordable Homes in Los Angeles: $500k and Less. (See the link below.)
Obviously, the other option is condominiums. Prices have taken a pretty severe beating here over the last couple of years, and there are a lot of opportunities available on this score. Please feel free to contact me if you'd like more information and best of luck.
Beyond schools, "family friendly" has different meanings to different people. Proximity to parks, pedestrian-oriented shopping, and easy commutes to various activities are weighed differently by different people. Certainly, north of Wilshire (and by extension north of Montana) and the Sunset Park (south of Pico, east of Lincoln) areas have a lot of nice tree-lined streets. But other solutions may work well for you too depending upon your preferences. See the "Schools" pages of my website for more detail.
You may reach me at (310) 508-6878 (cell).
Sunset Park is a great family friendly neighborhood. (90405) I specialize in the neighborhood and live in it too.
Feel free to contact me and we can discuss your options.