I'm giving/gave (depending on when you read this) a short talk on building apps (mainly WP7, little bit of Win8) at the Career Zoo event in Dublin on 22nd September (http://careerzoo.ie). On the deck I use there are a number of links listed. Instead of either distributing printed sheets, or even just expecting folk to write them down or something, I'm listing them here - that way there should only be one link to remember!
Useful learning resources:
Twitter feeds on o#wpdev, #windowsphone, #wpdevecosystem
http://www.codeplex.com/ is Microsoft’s free open source project hosting site.
The most important and possibly most useful for developers in Ireland is: http://www.microsoft.com/ireland/app/ - this one's got lots of resources to get you started with apps for Windows Phone 7, Windows 8 and Azure and also often advertises codecamps or other informal learning initiatives.