A while back, I wrote an article discussing the best choices of weaponry for people who cannot for any one of various reasons possess firearms (http://bit.ly/13Rip4e/). At that time, I recommended the use of a short sword or cutlass and a can of pepper spray. Since then I have had discussions on the subject with several experienced police officers.
They all agree that the cutlass is legal in California. Wearing it on the street may even be legal but would cause you a problem. Somebody would panic. The suggestion of a riot baton was made. In California the possession of a baton/ billy, even in your home can be charged as a felony. A baseball bat or any other club carried in a car for self-defense purposes is considered a billy club and is a felony to possess in CA. So keep a ball and glove with the bat. Never admit you are carrying it for self-defense.
Anyway, as a result of the discussions with officers I want to change my options slightly. At night instead of the pepper spray, carry a powerful flashlight. When you spray someone with pepper spray you will also be exposed to it, especially in a closed environment like in a home. Many criminals have been sprayed before and are more familiar with how it feels than you are and can fight through the pain. In this case it may become more debilitating to you than to the attacker. The intensity of the new LED flashlights will temporarily blind someone if it is shined into their eyes in the dark. It also destroys their night vision and helps even the playing field. If you question this give it a try on a family member at night. Shine a bright light in their eyes and watch their reaction. It will stop them in their tracks as they close their eyes and try to block the light with an arm or turn away from you. This will buy you time and give you the initiative to act in a way you feel is appropriate for the situation.
Learn your states laws and what you can legally carry.
As far as training, get as much as you can. For some people there may be physical constraints on this. I may be old but I could still swing a cutlass pretty well.