Javascript knowledge will be very useful because you can run Javascript on forms.
Plugins are coded in C# so that might be a bit more difficult.
The first thing you should do is download the CRM SDK, this is how you develop and extend CRM. The SDK has lots of examples and walkthroughs.
The developer training kit is also very useful because it has videos to help you learn as well.
follow the link below and it will link to useful development resources.
http://social.technet.microsoft.com/wiki/contents/articles/2490.microsoft-dynamics-crm-2011-development-resources.aspx
Ben Hosking
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