doing stuff with out being trained

ok so this is really pissing me off. i was asked to work for a co-worker as per my podcast stated. well i showed up and all i have is a check list of stuff that has to be done. well i dont know how to do 75% on the list no one showed me what to do and apparently no one can show me either. so im winging it and ive screwed some stuff up… oh well not my problem