How do I know which solar power kit is right for me?

I want to install some solar panels on my house, I like the idea that I am helping the environment as well as saving some money on my electricity bills every month. I am not sure we would be able to totally do without the power company but it would be nice to save some money.

How do I decide which solar power kit is right for my home?

Is there any independent body or group who can advise me, I don't fully trust anyone who is going to be making money if I buy the kit from them. I don't mind paying for someone to come round and do some estimates for me as to how much electricity I will need.