[rramadass]

I have all three editions. The 1st one is 32-bit only, the 2nd covers both 32 and 64-bit and the 3rd is 64-bit only.

If you can, buy the 3rd edition (this is one of the few books worth its price) and then pickup the 1st edition for cheap/free from somewhere. Try for Used/Secondhand copies to save money.

There is a lot to learn from the book; all of them necessary for a beginner to connect the dots and get the full picture. So don't get stuck on any one chapter/problem but make sure to cover all the chapters in sequence skipping over unnecessary details in the first couple of passes. As an example you don't need to know the nitty-gritty of PIC/GOTs/PLTs/Assembly minutiae etc. in the beginning but just understand the concepts of Relocatable code and Executable vs. Shared Object files.