PLINQ is a set of LINQ extensions that can be used to operate on lists in parallel through methods such as the LINQ Select statement.  You can just place the extension AsParallel before the Select call inside your LINQ statement and the software will attempt to take advantage of multiple threads in your system to perform the calculation in the LINQ statement concurrently when acting upon a collection.   If you want to get load balancing you can use the Partitioner.