i'm interested in picking up silverlight as another tool to use when appropriate, and i'm looking to get some suggestions on the best way to get started.
i have visual studio 2010, and can purchase expression blend if necessary (is it out of beta?), though i haven't quite been able to grasp the relationship between them.
are there any good books, tutorials, blogs etc that i should use to familiarize myself with silverlight 4?
There is a fantastic Silveright 4 Training Kit available on Channel 9:
http://channel9.msdn.com/learn/courses/Silverlight4/
It contains eight modules, 25 videos, and labs that walk you through features such as drag-n-drop, out-of-browser, etc.
I wouldn't worry about diving into Expression Blend until after you're comfortable with VS2010 Silverlight development. Once you're comfortable, Blend will allow you to easily add animations and other rich content (although all that is possible from VS2010 as well).
As for blogs and books, I suggest following Tim Heuer and Pete Brown on Twitter / their blogs. Pete's also got a Silverlight 4 book coming out, Silverlight in Action. I bought the early access edition from Manning.