Here are some ideas from stretcher.com:
Kid Rooms
And guess what? This article
CREATIVE KIDS' ROOMS is from MS founder, Kim Danger!

other tips:
*check Oops paint section at hardware store
*projecting scenes/shapes on wall and trace/paint (borrow projector from work, school or church)
theme ideas:
*flowers
*butterflies/bugs
*fairies
*fairytale/princess
*geometric shape (circles) / coordinating colors (brown and pink are a very "in" combination right now)
*angels

repurposing items is a great moneysaver. cheap sheets can be sewn into curtains or bedspreads, pillow covers or floor pillows. find thrift store frames and paint them all white (or brown, black, pink, blue, etc). add framed flower pictures (calendars are great), animals, scenery, or coloring book/children's book pages.
And remember, so often less is more. I'd stay with some simple basics, in case you need to modify it once she's settled in.