Clean and sanitize the food and water container once a day. The rat's bedding should be changed every couple days if your rat wants you to or not. If he has a stash of real important stuff, you can sort it out for him and return it to the cage. Don't use pine cleaners or any cleaner that can injure your pet s respiratory system. Ask the pet store or the pharmacy what would be a safe sanitizer to clean you rat's cage and accessories with.
Some people use peroxide and vinegar combinations.
This combination works great in the kitchen, too. Toys are important to your rat, they are much more complex and intelligent than some people give them credit for. Toys such as ladders, PVC tubes, wooden bird toys and boxes are great toys. My rats just loved the bird toys that had a treat hidden inside. It takes them awhile to figure the puzzle out, but they will get it.