Basically, each place has different rules. There are big companies that have services (which is why I lost my job, as they outsourced the work). I think most places use MS Word and I think dialup would be fine, but your computer may be slower when transmitting. I made $11-12 per hour when I worked for physicians. I did not have a quota to meet, but services may. I always had the boss breathing down my neck cuz there were 2 of us (transcriptionists) and 6 doctors so we were always behind. I think doing it at home may be different. I've known companies that pay you per page, per line, etc. You also need to make sure your home area is set up ergonimically correct, as all of those hours of typing (if incorrectly set up) could cause you to have neck, shoulder and wrist problems. The 2 most important things when you do transcription are good grammar and punctuation skills, being able to interpret foreign doctors and knowing medical terminology.
Hope this helps somewhat.