Virtual Transcription Niche Start Up

I'm planning to officially launch my VA business soon and I've decided that I clearly want to focus on transcription and typing services (manuscript prep, etc.) as a niche. I understand the basics of what I'll need to start out with, but I'd like to get some specific suggestions from experienced VAs. Since typing and transcription work will be what I do on a daily basis, what office equipment, software apps, or on hand research materials do you recommend as a must-have before I begin? (Or what could you not do without for your transcription work?)

Thanks!
K