Microsoft has some realy good guides in both XNA and silverlight to get developers started.
I was never into C# and infact i was never in anything Windows realted but taking a quick look at those guides realy amazed me how simple and effective they are.
I've said it a thousand times and I'm gona say it once more.
Microsoft did a realy good job regarding the developers.
If your more of a visual man then you can also watch youtube videos on tutorials.
There is a guy that has a channel for WP7 development starting from instalation to creating a complex app.
P.S.
All it needs is time, your brain capacity is never the issue.
Edit:
I forgot to give credit to the IDE (Visual Studio). The experience is just flawless.
I've had hard linux gurus gazing at it and wished it was cross platform and supported more languages.