I live in an area where tons of data is missing. I mean the whole areas with no street addresses, missing streets, missing bike routes, etc.
Is there a guide or special tools for preparing to make massive edits like this? Is there a particular work flow that people use or resources? How do I even get started?
Two things that I’ve noticed and that have helped me in similar but not such extreme cases.
JOSM is a massive time saver once you learn how to use it. It’s made editing a lot quicker when I’m working on similar tasks.
Try break it down into small tasks for yourself. It’s a lot easier to work on smaller pieces of a city/area than trying to cover everything all at once.
Ireland is currently working on something similar (example), I’m not sure how easily you can create your own private tasks for your country/area of mapping.
You don't have to try to use something as complicated as the full HOT style tasking manager. For personal projects something like SimpleTaskManager 1 or the Divide and Map Now 2 project can make this simple for smaller areas.
Then ask the neighbouring group if there's not even one on the country level. It's really best if you talk to those people who map in the area or next to it.
I'm gonna be giving a bit of contrarian advise here: don't force yourself. No-one asked you to do this all, so take it easy and one bit at a time. If you are a volunteer, just have some fun with it. When you don't feel like continuing anymore, don't.
Another piece of advice: "if you want to go fast, go alone; if you want to go far, go together". (But the latter is more work). If you live in a medium-sized (or bigger) city, maybe there are a few people interested in joining? Post to the local facebook group and do a small gathering with a cup of tea and map together.
I would recommend using Mapilio to get street-level imagery for your area that you can then refer back to when mapping bike lanes, streets, etc. You can record from a phone attached to your bike or car.