Yes it's a great idea to change your hair. I did it too. I got a much more stylish cut and made my hair much, much lighter brown with lots of golden brown highlights. 10+ years came off of my age in 2 hours when I made this change. What I did was go to
Hairstyles, Celebrity Hair Styles and Haircuts | TheHairStyler.com
You pull all of your hair off of your face and take a picture. Then you upload it to this site and you can try hundreds of hairstyles and colors on your face shape. It is very realistic and helped me find the perfect style and color. I took the picture of "me" to my stylist and had him do the exact same thing. It is reasonable. A 3 month membership is less than $15.
Another thing this site is good for is to help you find the right style. They have sample face shapes to help you determine whether your face shape (from the picture where you have your hair pulled back) is oval, heart-shaped, etc. Then the site recommends hairstyles that are best for your face shape.
I always thought I had a heart-shaped face and found out I had a diamond shaped face. And a diamond shaped face takes a little different ideal hairstyle.