Furniture, Wood and Cabinetry Finishing - Barnwood

I have a bunch of barnwood and plan on making various pieces of furniture out of it such as a bed. Do I need to do anything to the wood before I bring it into my home. In other words, is it usually moldy or does it have other health concerns I should adress before I bring it inside.

It is really hard to say. So much depends on what condition the wood is in. It may be perfectly fine but there is also a chance it is insect infested, mold is also a possibility. You should be able to see the mold. Bleach water will kill most molds - rinse well. Inspect the wood good for insect damage, sometimes cutting the ends will allow for a better inspection. I assume you plan to plane the wood down so it is all the same thickness - might be nice to do this first - don't forget to check for nails.

I have heard that vinegar will also kill mold if it is present, is this true? I live in Montana and I just acquired the wood. I had been outside all winter so I think that most of the bugs should be gone if there are any. Thanks for your advise.

I don't know about vinegar but anythings possible. It is also possible for insects to lay dormant in cold wood waiting for warm tempature.