There are many family friendly hotels in the Los Angeles area.
The key thing is finding a Los Angeles hotel that not only fits in with your budget, but one that is located in a geographically convenient place to where you want to go. A San Fernando Valley Hotel for will not be the best location if you plan on visiting Disneyland for three days since Disneyland is actually in Anaheim. On the converse a Valley Hotel would be perfect if you plan on visiting Universal.
Beach Hotels
Anaheim Hotels
San Fernando Valley Hotels
Los Angeles International Airport Hotels