Though you have mentioned your room sizes, you haven't given any details about it, i.e. where the door is or how many windows are there and their positions. Also you haven't told your extent of decoration, i.e. that is whether you just want to relocate your existing furnitures or you want tomake an addition or you want to paint it and change your furnitures. You should also have to mention your requirements as what all things you want to accomodate such as bed wardrobe dresser etc. This all aspects and many more is to be thought over before you start and plan accordingly.
BTW juhi is right that you can also look for pictures over the net or even can go through different interior design magazines.