You have almost 2 weeks to clean the house so it is totally do-able. Take a deep breath. Break it down. Which area of the house is the messiest? Do that first.
I would advice cleaning your bathroom, kitchen and hall first as these are the rooms that visitors see the most. Declutter each room too-get your kids (if you have some!

) to pick up their stuff. A nice candle or two in a sitting room always looks nice too, fresh towels in bathroom, some pot pourri in bathroom..you get the idea. You can leave the bedrooms til last. Just change the bedsheets, hoover and tidy etc the day before they arrive.
The easiest way is to just start. Just say to yourself "I'll tidy for 5 minutes". Then when you have tidied for 5 minutes, say "I'll tidy for another 5 minutes". Keep doing this until you have one room tidy. To my mind, there's no point in taking breaks in between as this will drag the thing on for ages, just knuckle down for a few hours and the whole thing will be done in a day or two. You can of course do it gradually if you want!
And remember that the sooner you start, the sooner you'll be finished!
If you have kids, get them to tidy their rooms-maybe give them a treat if they do it to motivate them. If you have a partner/husband, rope him in too. Delegation will help as you will have less work to do and it will get done quicker too!

Plus you won't feel resentful that its all left to you to do.