I will use the AdventureWorks database to demonstrate how to perform CRUD operations using LINQ. You can use LINQPad (a free tool) to execute your C# statements without going through the hassle of writing a program using Visual Studio 2008.
Launch LINQPad, add your SQL Server Connection and select AdventureWorks as the Database. Remember to select C# Statement(s) as the Language Type.
Create Record
1: Department newDept = new Department()
2: {
3: Name = "Consulting",
4: GroupName = "Consulting",
5: ModifiedDate = DateTime.Now
6: };
7: Departments.InsertOnSubmit(newDept);
8: SubmitChanges();
Retrieve Record
1: var department = from dept in Departments
2: where dept.Name == "Consulting"
3: select dept;
4: department.Dump();
Update Record
1: Department dept = (from dept in Departments where dept.Name == "Consulting" select dept).Single();
2: dept.GroupName = "Consulting Services";
3: dept.ModifiedDate = DateTime.Now;
4: SubmitChanges();
Delete Record
1: Department dept = (from dept in Departments where dept.Name == "Consulting" select dept).Single();
2: Departments.DeleteOnSubmit( dept );
3: SubmitChanges();