abapprogramming.net
SAP ABAP Programming is a website with 550+ articles on different topics like SAP,ABAP programming,Reports,Bdc,Scripts,Smart Forms,ALV,ALE,IDOC,EDI,User,Customer Exits,BADI,BAPI, FAQ'S.
It has number of ABAP topics in a proper order with detailed lessons to learn about SAP ABAP Programming completely.
It has 700+ RSS readers and the list is growing.