I currently have the BPP edition of books for f5-f8, for exams in december 2014 and june 2015 , will these same books be valid and useful for the december 2015 sessions of exam ?
I am not sure about F6, F7 and F8 because I do not teach those three papers. Either look on the ACCA website at the syllabuses for September onwards – at the end it lists any changes; or alternatively ask in the forums for those three papers and the three different tutors will be able to help you.