Step1
Seriously, scrupulously clean your home--this may take a whole weekend or two or more, but it is essential. Don't plan on having much of a life until it's done, just before your house is listed. Ask a good friend to tell you if there is ANY odor--get rid of it! Unless you're good at it, hire someone to do the windows--let in every possible bit of light. Start with the kitchen: scrub all the nooks and crannies. If there is anywhere that tends to be yucky do what you have to to rehabilitate it--paint under the sink, strip off old floor wax, put down shelf paper--whatever it takes. If the fridge or any appliances are part of the deal, go over them with a magnifying glass. Same for the cabinets. Be obsessive. Ditto with the bathroom(s). If a Q-Tip with Clorox on the grout is required, so be it. Buyers won't notice specifically notice that the grout is dirty but it will register negatively. The "public" rooms--dining, living, family--should be dusted, vacuumed, mopped, woodwork wiped down, and completely decluttered. In fact, consider your bedroom pretty public during this process. If you have animals that shed or use the litter box, consider fostering them out. Otherwise, confine them to as little space as they will agree to and keep it as clean as you can. Likewise with children.
If you can cajole or guilt your friends into helping, stoop to any bribe you must--a nice dinner (OUT!) is actually a pretty reasonable price to pay, but don't serve beer until the job is done.
Step2
Show the prospectives how much space they can fill up--even if it is an illusion. If the fridge is built-in or comes with the place, you want to show people how much they can fit in it--NOT by showing how much you do, but by emptying as much as possible. Get rid of all those half-empty jars and bottles--less is more! Same goes for the pantry and the cabinets. This means getting rid of all but the basics--even if it means storing some of those candied kumquats and mismatched pots and pans. Ask a friend's help and some garage or basement space if you can't say goodbye. Again, you want to convey the luxury of space and order. Ditto for linen closets, built-in bookshelves, etc. In fact, you should keep your own storage space (bookcases, entertainment center, etc.)ridiculously neat. Then these will not distract from the gestalt and will convey to the buyers that you are serious and responsible (again, even if it's an illusion). Let the prospectives imagine how much better THEY will fill all those areas.
Step3
Outside: if your property has been properly "staged" it should have that allusive quality of curb appeal. Seasonal annuals can easily be planted for color and interest, even by the blackest of thumbs; or, put something growing in a handsome container for the porch or stoop.
The yard itself: if there are animals in your household, be sure there are no land mines waiting for those who want to walk around it. This can be a Herculean task if you haven't kept up with it. Not everyone tolerates the little critters. It should appear as if nothing four-legged lives here. Ditto for kids--no toys, big wheels, etc. should be left out. This may be time-consuming on a daily basis, but it will be impossible if you don't start with a clean slate. Needless to say there shouldn't be a pile of tools, boards, etc. "hidden" behind the house.
Step4
And finally, that place between outside and in, the dreaded garage. Most of us have the tendency to stow there the clunky things we can't think of where else to put. This is OK if there's plenty of room for cars and it looks like Det. Monk did so. Maybe you have a shrink friend who knows some OCD patients you could hire? Like dusting, it is a thankless task as no one will notice unless it is not done.
Novice 
