What can i do about my room?

I have recently moved into a new bedroom and have a new bed.There is a link that shows a pic of the bed.my walls are light blue and purple and i need some creative ideas to make it look better mabye things to put on my pinboard , nice paintings , what to put on the shelves on my bed any other ideas would be great. I am writing this for my little sis so the age group for stuff would be 10-14 ,Thanks . http://www.google.co.uk/imgres?imgurl=http://i.ebayimg.com/00/%24(KGrHqUOKnQE4S1e9lFcBOH%2B66itgw~~0_35.JPG&imgrefurl=http://www.ebay.co.uk/itm/New-Vision-Maple-High-Sleeper-Cabin-Bed-Wardrobe-/190555452820%3Fpt%3DBeds_Mattresses%26hash%3Ditem2c5dfd7594&usg=__OKEWoDH0nsT8yYdbO5aJnpAr7MQ=&h=224&w=300&sz=11&hl=en&start=0&zoom=1&tbnid=UuD8IWx2C2zI2M:&tbnh=141&tbnw=200&ei=nSgnTtqWOJH4sgaQqNChCQ&prev=/search%3Fq%3Dnew%2Bvision%2Bcabin%2Bbed%26hl%3Den%26biw%3D1024%26bih%3D432%26gbv%3D2%26tbm%3Disch&itbs=1&iact=rc&dur=360&page=1&ndsp=8&ved=1t:429,r:0,s:0&tx=108&ty=56