Ok, you've left it a bit late to start so you'd better get going:-
1. strip all the beds and get it all washed and dried
2. air all the mattresses, duvets, pillows, leave for 3-4 days before making up again
3. wash and dry all towels
4. tackle as much as you can of the kids rooms, but ensure you've got all laundry
5. wash and iron all dirty clothes
6. make sure all wardrobes and drawers are sorted and iron any clothes that need it
7. dust, and damp cloth wipe, ceilings, walls and skirtings
8. clean windows, and frames, inside and out
9. dust and polish in general
10. hoover/wash all floors
11. deep clean the kitchen and sort cupboards and drawers, pay particular attention to those hard to get places and the cooker/oven
12. make sure that the vast quantities of rubbish you've accumulated are taken to the tip
13. sort contents of fridges and freezers, defrosting where need be
14. as you go round the house complete all those little DIY jobs that you've been 'saving' up
15. don't forget to take a little time for yourself
simples