Getting started with asp.net 3.5

hi, I have been a ASP.net 2.0 Web developer.

In asp.net 2.0 , while creating any application I used to create a DataSet1.xsd where I create the Table Apadters of all the table and write all the queries in its associated TableAdapter.
Then Used to call these quires in the code behind page of the web page.
Now , I want to use asp.net 3.5  but little confuse how to do architecture based work in asp.net 3.5. How to use sql quires in it.

Should i use the same way as I used in ASP.net 2.0 ? or I should go for Linq? or there is any other way for it in asp.net 3.5?
How to develope web appliaction in asp.net 3.5 ( like tier based work  and architecture based work.)


Thanks







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