How do I find out how a new car radio connects to my car?

I have a 99 honda accord and the radio is is bad shape. I will have this car for a while longer and am currently shopping for a new radio. I'm new at this and need some help. 1. How do I find a decent radio at a decent price, 2. How do I know that it will fit in my car, and 3. How can I find a holder for the radio so it will sit in my radio dock securely?
 
Top