Changing Hosts

Hello, I currently have simplehost (who charges $90/year). I want to change my host at the end of 12 months. Thing is, I don’t know how to backup all my logs (so I don’t lose every post I’ve written and all my users, etc.) and my database and tables. I also purchased my domain through simplehost, so I wanted to kill it and repurchase it through godaddy.com or something. Can anyone here please help me figure out how I can do both of these things without losing my data (or domain name)