I forgot, also look into what discounts the offer. When I was looking into motorcycle insurance Progressive was paying for the cost of having the bike lojacked and giving a discount from then on out. Insurers often times have discounts for things like that which pay back all or some of the investment to reduce the risk of theft or damage.
Also, not all vehicles cost the same amount of money to insure. If you get a more sturdy vehicle or one that's less likely to be stolen, you'll pay less.
Assuming you don't already own the vehicle in question or have a choice.
hedwards: I haven't shopped in a while, but the best thing to do is to figure out how much coverage you really need and just buy that.
As a general rule, the higher your deductible the lower your payments are going to be. So, I tend to recommend people just bite the bullet and set aside enough money to cover that and go with a higher deductible.
Also, just comparison shop, I think most of the major insurers will have an online quote system where you can get price estimates.
I assume you're not looking for motorcycle coverage as there's only really a couple of insurers that are worth buying that sort of insurance from.
langurmonkey: I'm doing this for my mom. I'm interested in a website that will help me find the cheapest car insurance because most insurance companies charge her too much due to an accident some years ago. She can't afford anything but the cheapest nowadays due to the bad economy...
That's understandable, that will be tough, but she may need to go to an agent and have a policy tailored to her needs. She may need to have coverage that's limited or agree to monitoring while driving.
I don't like the idea, but in some parts of the US, you can agree to allow the insurance company install a tracking device and receive a substantial discount on coverage. Basically it would probably track how often she slams on the brakes or hits the accelerator and such.