Spot cleaning should be done daily or possibly every other day. Full clean outs should be based upon how large your cage is. A very large cage 1,000sq in+ may only need to be cleaned every few months while anything under that should be cleaned on about a monthly basis or so. As cypher says, never remove all the bedding at once. Instead, remove 1/4 to 1/2 at most per every one "full cleanout". Make sure not to rinse off toys and keep the set up essentially the same if you can
