Make it a party. Call your friends, the more organized and clean-centric the better, offer them pizza and beer. If you don't have any friends, make some. If you want to, decorate or buy some cute aprons and gloves for folks to wear. The one thing that's really important is that you only invite people you trust because they are going to see a side of you that, if you're anything like me, is probably pretty grotesque.
The first thing you want to do when they arrive is throw on some tunes. The more fun the better. I like Rufus Thomas or the Xanadu soundtrack, but pick whatever gets you and your friends moving. Start with one room. Declutter!!! Get rid of stuff you don't need. Don't look, just toss. Come on, do you really need that essay you wrote in the ninth grade? Don't be a bitch, chuck it! That should be your motto right now. Keep saying it to yourself. If you really can't do it pass it on to one of your friends who knows you well. Let her decide what's junk. I know that's tough but if you're going to act like a baby, I'm going to treat you like a baby.
While this is going on in one room and you are crying to your selected friend that you really need to save that lint ball you picked off of your ex-boyfriend's sweater last year send another friend into another room and have her go through your crap and put it into manageable piles. I am a big fan of piles, I have even been called "the pile princess" at times, with good reason. It's going to make the decluttering go a lot faster later, I promise.
So, now that you've dealt with decluttering one room, you are ready to address the piles your dear, patient, caring friend has made. The first thing you want to do is take any piles that belong in another room and place them where they belong, to be dealt with when you reach that room. Then you want to go through them and chuck things with abandon, similar to what you did in the first room. Once you are finished with piles upon piles of crap, take a break. Order your pizza, pass out the beers, or soda, or whatever your beverage of choice is and crank up the music. Celebrate your floor space. Yup, if you have done this right, you should have a dance floor now. Scoot the coffee table out of the way and bust out your sweet dance moves. Sing, skip, jump, whatever floats your boat celebration style!!!
Okay, break's over. Time to clean. You should know basic cleaning. Wipe down tables, if you have pets, de-fur the couches and chairs. Little tip for those with out a vacuum... Take a rubber dish glove and get it wet. Rub it around in circles on the furniture and before you know it there will be gross balls of yuck that you can easily pick up and deposit in the trash. (I saw this on "How Clean is Your House?" on BBC. It works.)
Break out the broom. Sweep. Sweep again. My favorite little trick is the "double sweep". It's very exciting to see how much dirt you get the second time around. Mop. (This sequence should be repeated for every room in your house.)
CONGRATULATIONS!!!!! you have made it through the first step to having and keeping a clean house. Enjoy it for the night. Relax, put your feet up, breathe in the air that does not have the least bit of nasal burning funk!!! (Don't get too comfortable because day two is looming just around the corner.)