Ultimately, I think the best thing to do is just jump in and start a project that you're interested in. Accept the fact that you'll be hitting StackOverflow all the time, and when you're there, pay attention if you see comments and answers from Jon Skeet, Eric Lippert, etc. There are some decent email link-dump newsletters that are good and have a .NET slant, like Morning Brew[1] and Morning Dew[2], which can help keep you up on what's new, and often link to articles explaining various nooks of the .NET world. Avoid CodeProject - most of that shit is old, poorly written, and as often as not incorrect. Once you have your bearings a bit, C# In Depth[3] is a great resource on the nittier, grittier details of C# and the .NET framework.
[1] http://themorningbrew.net/ [2] http://www.alvinashcraft.com/ [3] http://amzn.to/1fv0zNH
Feel free to PM me if you get stuck. I'm no one special but have years on the stuff (and was in c++ for years prior).
Download Visual Studio Community (if you don't already have it) then try out one of the project templates. The tooling is excellent and it's very easy to get started.
Then it depends on what kind of code you need to write. I work with web/information systems so the focus is on SOLID over pure performance. Using DI and TDD is more important than being an absolute language expert.
Drop me a line if you want more details tips; I've helped a number of people make the transition. Email is in my profile :)
A book that should get you up to speed on 90% of C# relatively quickly is Professional C# 5.0 and .NET 4.5.1 by Jay Glynn. It's not got info on C#6 and .NET 4.6 yet, but the differences there are pretty quick/intuitive to pick up.
Afraid I can't help to much with the databases portion - it's something I'd like to find a book on myself! Good luck on the career switch! (:
If you are just getting started I always recommend the msdn tutorials.
https://msdn.microsoft.com/en-us/library/aa288436%28v=vs.71%...