A natural question. Unfortunately I don't have a great answer for you.
Most books have downloads. I don't know of any more advanced books that have the same kind of DVD screencasts. Most authors will answer questions (with varying degrees of responsiveness).
If you're feeling confident with what you've learned so far, then you're probably ready for one of the more complete C# books. This one was really a beginner's introduction and there are lots of books out there that cover a lot more topics in greater depth. They move a lot faster and usually don't have as many Try-It style samples or exercises, so for anyone who isn't fairly confident in what was in this book, some of those books will be pretty hard.
I'm actually writing a more in-depth C# book right now. It should be available some time next year, maybe in March? (I don't remember the production schedule right now.) It will cover a lot more material. It won't have Try-Its or screencasts, but it will have exercises at the end of each chapter.
I re-read your Introduction to see what C# had to offer and the topic of “Games” and possibly “databases” seems to be appealing.
Games can be fun. A lot of games these days do some pretty complicated graphics. If you want that kind of game, look for a book that focuses on the graphics using Direct3d or OpenGL. I've seen a few books that do simpler games. Mostly those books don't produce the sorts of high-quality games you might install on your phone or tablet, but they can be an amusing way to practice your C# skills.
Database programming is a huge topic. My book Beginning Database Design Solution
can be helpful for designing a database. You'll need a different book to learn about how to program with a database in C#.
A couple other fun topics are phone programming and WPF programming. (Those topics also go well together because you can use WPF to program the phone.) I know you can get cheap copies of my book WPF Programmer's Reference
So there's lots to study. Unfortunately I don't know of any books right now that I can recommend, mostly because I haven't looked at any lately, not because I hate all the books out there.
Sorry I can't give you a better answer. Whatever you decide to pursue, let me know if you have questions and I'll try to help if I can.