would recommend the patter manual - cant remember who the authors are but gives a nice run through of the exercises.
campbells book is very detailed and gives you pretty much everything you'll need.
get a copy of lasors for referencing, free to download but quite handy to have a hard copy for the course and then presumably as an instructor thereafter. also a copy of the poh for the a/c you'll be doing it on is very useful. (if its in a pa28 then i have a copy of one i can email over, pm me)
best of luck with it, get lots of pre-study done so you can concentrate on the exercises through the course.