Can't believe this guy has his own web site. The ledged will live on forever....
The best thing you can do is set up a secure observation post. You want maximum visibility but also protection against incoming weapons fire. Since car windshields work so well as deflecting bullets you might want to visit the local junk yard and buy five or six windshields out of broken cars. A few tent poles and some duck tape and you will have a very secre position from where you can watch the whole neighborhood.
There are lots of boobyttraps and stuff like that you should look into but it would not be appropriate for me to discuss those in public. But just be thinking about ways to barricade all the streets in and out of your neighborhood if you have to.