What is a Client Care letter, should I have one?

Everyone who instructs a solicitor should receive an engagement letter and terms and conditions, which set out the contract between them and the firm, you should not be charged until you have signed this letter.
The letter should set out amongst other things:

 What they are going to do;
 Hourly rates and how charges are calculated;
 Cost estimates for your matters;
 Who your lawyer will be; and
 What you are liable for