Just a quick word - I am affiliates for the programs and services below, but that's because I have used them for years (without being an affiliate) and love what they offer.
I never used to get my interviews transcribed, but I started using Rev and have never looked back. It's $1 (USD) for one audio minute and the turn around is super quick and the quality is fantastic. If you are a new customer and use this link, you'll get $10 off your first order.
I am a huge fan of formalised learning and being taught the right way to do things. When I first explored doing a bit of freelance writing, I wanted all the information right in front of me, in one place and at one time.
Within weeks of completing the course I had my first commission and six years after doing the short online course, am a full time freelance writer.