While I kind of disagree about the book being "useless" without prior knowledge of C# (or
VB.Net), here's two key points
1) The book doesn't confuse you a lot even if you have no idea of C#. With all due respect to Imar, this book pretty much only scratches the surface of C# programming. It covers basics, but that's it - like it should be in this kind of book.
2) If you want to actually learn how to do .Net programming, even if you would want to focus on ASP.Net, I would seriously recommend getting an accompanying C# book. I have read
Beginning Visual C# Programming 2012 and I can recommend that one.
So shortly, if your idea is to learn to do the basics of C#, enough to apply to ASP.Net programming, go with this Imar's book but if you want to seriously aim higher, I'd say read that Beginning C# book and continue from there to this one.
If you decide to go with the Beginning C# first, then if you know _anything_ about programming, try to read chapters 8-14 and then jump to this ASP.Net book or if you have no idea what programming even means, I'd say read the chapters 1-14 and then continue to this one. Chapters 15-26 are definitely not useless, but if the idea is to concentrate on web programming, then I think after chapter 14 it's pretty safe to jump to this Imar's book.
Oh and everything in this Imar's book is in
VB.Net too, so if you have, say, VBA background, you'll have no problem here.
Hope this helps you or someone else :)