Well I wouldn't do wallpaper (bad excpirence).. lol.
Anyways colors that are bright and cheerful,
lime green
lavender (very calming)
light blue
light orange
Good idea, try putting squares, simple but makes a room totally different. You don't want your room to be to crazy, so keep it simple.
http://images.lampsplus.com/images/F4041...
fun furniture!!
http://beatrice-dabreu-designs.co.uk/pro...
http://thumbs2.modthesims2.com/img/7/5/2...
carpets :)
http://s3.amazonaws.com/curbly_uploads_p...
something you should do, mixtures, flowers, funnnnnn!
https://ssl.adhost.com/noveltylights/pro...
lamps
http://img.alibaba.com/photo/11137432/Pa...
http://4.bp.blogspot.com/_Zmva9qcO2j4/R2...
Well, there ya go! your room will be awesome! :)