How can I design my room to be feng-shui style?

There is a free book on Feng Shui especially with regard to the bedroom design being given for free at the site below. You might want to check it out.
References :
http://www.squidoo.com/freefengshuitips

I think you want to put the following colors in the following positions:
Blue - east
Red - south
White - west
Black/dark colors - north

Good luck!
Blake
References :
http://en.wikipedia.org/wiki/Fengshui#Bagua_.28eight_symbols.29

fengshui is not a decorating style. it is a form of divination, in which you arrange the rooms in your house to optimize your life - by using more the areas in your house with good chi or energy. the locations of this good and bad energy in your house can only be "calculated" using certain fengshui techniques like flying stars, 8 mansions, etc.

regarding color, basically you can have any color you want. just be careful in using bright red, orange and yellow, as they can activate areas with good energy or with bad energy. it is good if by accident the area is good. but if you painted the area with bad energy, then accidents will happen.

the nature of this good or bad energy has nothing to do with vibes or it cannot be sensed by psychics.

arrangement. fengshui is more than the arrangement of furnitures in a rooms; it is more like the arragement of the house in a location - as they say in business, location is important, so as in fengshui. another is the arrangement of the rooms inside the house is important to optimize your life and those of its occupants - for example, you would want to put where you live more like bedrooms, dining, living rooms in the good chi areas; and make the bad chi areas into garages, toilets, etc. as with the kitchen, there is a special formula for this, because the kitchen is responsible in attracting wealth into one's life.

bed placement… hmmm… not that important for me. in fengshui, the distribution of this good chi areas and bad chi areas in your house is dictated by the degree which you front main door (not the metal gate, but usually the wooden door) faces - where the yang comes into your house. this is used to "calculate".

if you have a good degree, then the rooms are properly placed, then no matter how you arrange your furnitures/ beds inside the house - it's all good.

objects - same as bed; though i would not advise in using bagua, mirrors or chimes esp inside the house as most books recommend.

fengshui is not a decorating style. you can have a very american or mexican house and still have a good fengshui'd house.
References :