I have just finished this series after a good portion of the last five years waiting for each installment.
Skulduggery Pleasant, created by Derek Landy, is a skeleton detective who meets an eleven/twelve year old at her uncle's funeral. Skulduggery introduces Stephanie (who later becomes Valkyrie Cain) to the world of magic and sorcerers.
These books are great! They seamlessly merge sassy wit and magic (my favourite type of book) to create a stonkingly good fantasy adventure series.
I must add that these books are very funny and the series just gets better as it progresses!
Well worth a read - if not several.
I must also add that you must read the biographies and little blurby things at the back/front of the books! they are really amusing and also sort of tell a story from start to finish!