I've been working my way through this tutorial. I got stuck when it asked me to make a class that inherits from TableStorageDataServiceContext. I can't seem to find the .dll or namespace or whatever.
DataServiceContext works fine. That tutorial is a bit old. Has the class been moved or no longer exists or something?
The tutorial that you're following is from when Azure was only in CTP, some of the class names changed when it came out of CTP (they've been stable since then). The class I think this is now meant to refer to is TableServiceContext.
It is in the Microsoft.WindowsAzure.StorageClient.dll which is probably installed in C:\Program Files\Windows Azure SDK\v1.2\ref if you didn't change any of the settings while installing the SDK.
It might be worth finding a more up to date tutorial though, I'm not sure what other minor differences there might be.