If you are moving your work from an old Dynamics instance to v9, there are a few SDK to know about before you get started.
First – there is no SDK to download anymore.
Well, there is, but you do it through Nuget (and it’s great).
To install the core SDK framework – use the following Nuget command.
Install-Package Microsoft.CrmSdk.CoreAssemblies -Version 184.108.40.206
This will install all the core assemblies you need (i.e., not things like workflow assemblies).
To get the workflows you would need to execute the following Nuget command;
Install-Package Microsoft.CrmSdk.Workflow -Version 220.127.116.11
Different from the last few versions of Dynamics where you could get away with re-using SDK tools between different versions, with v9, you now need to download the updated set of tools via Powershell and use them from there.
Before downloading the tools, make sure you are in the right directory to where you want them installed (i.e., not system32).
After you have downloaded them, the usage of the tools is relatively the same (I’ve only played around with the PlugIn workflow registration tool).