HAI FRIENDS- HOW TO LEARN ABAP

Hai

I am very thankful for all those who are actively participating in sdn forum.It is the best way of updating knowledge.Coming to this post basically i am an sd consultant, and i am willing to learn abap (sd perspective). The problem is even though i got huge material, it is not so simple to understand about edi, idoc,ale prog,user exits, queries etc .I request you to provide me material to learn abap in a sequence and which can be understood some what easily (pls dont suggest abap in 21 days)

Thanks & Regards