The above all comes from experience.
In the case of insurance rates, I was actually very surprised by this. I was assisting my mother-in-law about 2 years ago with getting a new car and insurance coverage. The insurance quotes were astronomical: more for her for 6 months for a $6,000 used car than my wife and I pay combined for 2 $45,000+ vehicles for a full year. I questioned why, and it 100% had to do with credit history, not at all with driving record.
When it comes to what most people expect from good or poor credit, loan rates, it is often very apparent. What is your home's mortgage rate? What are your credit card rates? A new car rate might be 1-2% points higher for you than the person sitting at the desk next to you buying an identical car (and therefore $15-$50 more per month).
I was able to refinance my house a couple of years ago at a rate of 2.85%. Based on my old rate, and with paying the same monthly amount, I was able to reduce my re-payment term from about 15 remaining years down to about 11 remaining years. Again, same payment monthly, I was able to save about 4 years or 48 payments. Simply moving from 5.25% down to 2.85% ultimately will save me ~$50,000 within about 11 years, so about $4,500/year. That is potentially life...and retirement...altering. And, because of the lower rate, my principle balance is declining much more quickly, so every month I have more-and-more equity in my house.
Anyhow, in terms of research, I am sure you can easily seek it out online. Also, check out Experian (or freecreditreport.com) for more info as well.