How do I file for legal separation with the intent of obtaining a non-contested divorce?

Why bother to seek a separation if what you really want is a divorce? The documents and the expense are about the same. However, first things first: consult an experienced family law attorney. It's almost always worth the investment. He or she can advise and represent you, draft the various papers, and generally keep things going as smoothly as can be. The process for obtaining a legal separation is like a divorce: your lawyer drafts up a summons and petition, often along with a Motion for a temporary order, files them with the Court, and has then served (officially delivered) to your spouse. If there is a temporary order required, s/he can obtain a hearing on fairly short order.

Whether or not the divorce will be contested is out of your control. If you want to get a divorce, just file it and don't bother with a legal separation.

This is illogical. You should hire an attorney or meet with the free Family Law Facilitator at your Courthouse.

I don't believe you file for a legal separation. You can have an agreement with your spouse regarding a legal separation which would include property spousal support child support and all those other issues. You would still have to file for a divorce at some point in time if that is what you want.