This is one thing you just can't leave out. The wood shavings have to be changed and the accessories and tank have to be scrubbed and rinsed with warm water. Some books recommend that you clean your hammy's "litter area" every day and change the wood shavings weekly. This is fine but you can use your own judgment as well. Cleaning its "litter area" isn't always easy - they tend to kick their wood shavings around. Some hamsters purposely move the shavings aside! Change the shavings when you see the need to. Remember that uneaten fresh food will need to be removed.
You can use vinegar and diluted amounts of a disinfectant to get rid of urine stains . Remember to rinse thoroughly and leave everything you have washed to completely dry off or dry with a towel, before you put back your hamsters. Your hammies can stay in a smaller tank or carrier whilst you're at work.
If you have any cleaning tips to share, please do!