Union apprenticeship sign-ups near Knoxville - what worked for you?

I heard of an apprenticeship with paid on-the-job training for people changing careers. I am in Knoxville, in case local advice matters. The application needs a diploma or equivalent, a driver's licence and a short aptitude test. Did anyone go through it?

Thanks for writing this out. I went through something close to it 13 months ago, and it got easier once I kept a simple log of every call and form.