The amount of energy your solar panel will produce is rated by watts. For example, if your solar panel is rated 100 watts, then on a clear day, your solar panel will produce 100 watts per hour. To find out how much electricity you need to produce, look at your electric bill and divide the total by 30 days and then divide it by 3 as there is generally bright sunlight one third of the day.
When researching for a good solar panel installer, don't forget the Internet. Yes you may start out in the phone book, but the Internet will give you a lot more information as well. You may find testimonials from other clients and ideas for contractors that you may not have realized are out there.
If after installing solar panels you find that you are producing more energy than you need, you can sell the extra energy that you produce back to the electric company. This method will help you recoup the cost of your solar energy system's installation and parts. Additionally, after you have recovered your costs, you will be making a profit.