Are you doing other dev work on windows? On which IDE? If it's VS, then there's no need for an additional IDE just to read disassembled code: debug your app (or attach to an external app), then open the disassembly window (in the default settings, that's Alt+8). Step and watch memory/registers as you would through normal code. You might also want to keep a registers window open (Alt+5 by default).
Intel gives free manuals, that give both a survey of basic architecture (registers, processor units etc.) and a full instruction reference. As the architecture matures and is getting more complex, the 'basic architecture' manuals grow less and less readable. If you can get your hands on an older version, you'd probably have a better place to start (even P3 manuals - they explain better the same basic execution environment).
If you care to invest in a book, here is a nice introductory text. Search amazon for 'x86' and you'd get many others. You can get several other directions from another question here.
Finally, you can benefit quite a bit from reading some low-level blogs. These byte-size info bits work best for me, personally.
