When you start working with Silverlight you have got to unlearn the concepts used while working in Flash. Silverlight is completely different experience of working on 2D animations. I am hoping it gets better with the newer versions.
The first concept to unlearn is the "Stage". You call your working area in Flash as Stage. Whereas, in Blend there are various Canvases that you work with. Every 'Group' of objects you create is a Canvas which can be animated on the timeline.
In Blend, unlike Flash again, the "timeline" works with units like 'seconds' and not frames. So, all your tween animations are possible to create as well as you can create them in Flash.
You can simply download Expression Blend 2 from Microsoft website:
Here's a link to learn and view some of these basic concepts:
This is it for today..
Keep watching this space for more updated on Blend 2 and Silverlight... :)