APO ABAP Related planning book

Hi All,

I need some links to tutorals to APO for abap related stuff.All that I have seen so far was all functional link help. I want to know some overview for the planning book, it will be good if i get some docs where it is explained pictorial. ANd sample codes for the extraction of planning book datas and uploading of planning book data.

Also I want the list of frequently used BAPIS with their functionality. ANd also suggest what else and how can I/ and how much to learn ABAP related part of APO.

BAsically I guess planning book is kind of a collection of infocubes. Incase the infocubes is to be created it will be created by the BI people but leat the abap part of it will be a gr8 help.

Thanks,

ANu.