I Got started with these videos
http://www.asp.net/web-forms/videos/data-access/how-do-i-with-linq/how-do-i-linq-to-sql-overview[
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No matter what you do ORM, LINQ or Enty model , the ability to write good linq queries and knowing the pitfalls and performance hits is key, also it helps tremendously when working with arrays.
Telerik is also giving away their version of ORM for free, www.telerik.com , they have excellent video resources and their forums gives help even to members who didnt buy a subscription (FYI their subscription is very well worth the money).
Hope this helps