OK, let's play with LINQ4SP again.

You can download Beta1, write a simple query, create a new list item and lookup fields. In the next part I'll show you how to delete an item from a list:

        [TestMethod]
        public void DeleteCreatedItems()
        {
            using (AwContext context = new AwContext())
            {
                var q = from subCategory in context.ProductSubcategory
                        where subCategory.Title == "new sub category"
                        select subCategory;

                foreach (ProductSubcategory psubcat in q) psubcat.DeleteOnSubmit();


                var p = from product in context.Product
                        where product.ProductNumber == "AA" ||
                            product.ProductNumber == "Double test" ||
                            product.ProductNumber == "Date test"
                        select product;
                foreach (Product prod in p) prod.DeleteOnSubmit();

                var z = from pc in context.ProductCategory
                        where pc.Title == "new product category"
                        select pc;
                foreach (ProductCategory prodcat in z) prodcat.DeleteOnSubmit();
                
                context.Submit();
            }
        }