dosage calc and medical terminology
books are highly recommended after orientation... i bought them after orientation was done.
the medical terminology book is important b/c in the hand out they gave there wasn't a list of terms. everything is in that book. it also comes with some flash cards; i found them really helpful.
as far as dosage calc book goes, i found that really helpful too. definitely helped get rid of some rustiness as far as basic math is concerned (go figure, i can do college algebra but basic math killed me when i first started learning dosage calc, haha).
anyway, i bought the other books a week before school started. you really won't need those until class starts, and i agree with mike, try to find them used. i bought my books all new b/c they had just put out new editions. ugh.
hope this helps!