As u have seen,these days in IT field people from Sap are most wanted.Do u think its right to do some Sap course?Or its bubble will also blow up in few months.which module should a fresher (or how much) do to get first a break in this field (even if its a small job) , as u have seen its very very big and complex.
Is there any effective way to do it except to attend its highly expensive classes??
could someone tell me online link where i can find the good ebooks regarding Sap/ABAP and related software(i.e ABAP editors..) for home learning??(or it is not at all possible to learn effectively from home??)

I would not want that. As SAP end-user I can say that this is a terrible software, for the end user. It is slow, has awkward GUI, and once more it is SLOW. I curse every time when I have to use it. Honestly :-). But again perhaps you can help to make it better...