There is a lot of information (and misinformation) available regarding mattresses and how to get a good night's sleep. Here is just a sampling to assist you when considering getting a new mattress.
Assessing whether you need a new mattress Mattress Sizes and which is right for you Tips on shopping for a new mattress Tips for getting a good nights sleep
Assessing whether you need a new mattress
Mattress Sizes and which is right for you
Tips on shopping for a new mattress
Tips for getting a good nights sleep
Here are a few other sites you can visit to learn even more about getting a good night's sleep:
Kansas State University Web MD Article on Good Sleep Family Doctor dot Org article on good sleep
Kansas State University
Web MD Article on Good Sleep
Family Doctor dot Org article on good sleep