After renting in California for over 17 years, here are some of the issues I have found which you really need to be aware of BEFORE you sign your lease.
1.) Neighborhood -- is this a safe area?
2.) School District -- if you have kids, this is very important - but even if you do not have children, how close is this school to the property that you are buying or renting? Will there be a tendency for students to linger near your home?
3.) Location, Location, LOCATION - how central is this to the areas that you frequent?
4.) Reputation of landlord or real estate agent - can you trust this person? Do they have a registry with the "badbusinessbureau.com" - where they have manipulated and harmed previous clients in real estate or rental transactions?
5.) Unforeseen health risks - this is major in California:
a.) How close is this to the beach (possible tsunami)
b.) How close is this to a major fault line (possible earthquake damage)
c.) Mold issues - (create possible health issues)
d.) Lead based paint issues -- homes that are older than the mid 1970's will have you sign a waver stating that the landlord/previous owner is not responsible for your health - or unborn children.
e.) How close are you to a major freeway, are you up-wind - or down-wind... carbon monoxide poisoning is REAL... it causes a lot of different side effects, google this, you will be amazed.
f.) How close are you to airplane traffic, major mall traffic, land fills, or areas that may be soon reconstructed into a housing area... (i.e., canyons filled in order to create a new condo across the street).
g.) Wild-life in your area, particularly if you have pets that like to go outdoors
h.) Shared walls with neighbors -- this is major if you value your privacy and dislike outside noise invading your home.
i.) Location within the community, are you near the gate where you will be expected to buzz other neighbors with UPS packages? Things like that can become very obnoxious over a long term stay in a certain location.
These are just a few of the things that I've experienced.