I'm also working on learning to do more of my own bike maintenance. The approach I've been taking is really a step by step/task by task approach. I tend to take more a 'just in time' approach to doing maintenance rather than trying to absorb a tsunami of information on a whole range of maintenance work. Many jobs are fairly simple once you know how although there can be fiddly things to think about that can go wrong if you don't do them right.

I'm at the point where I've:
changed tires (minimum thing any cyclist who rides any distance should know how to do
Lube chain
Changed chain
re-greased headset
re-taped handlebars
changed cassette (see my other post on this - I always make every possible mistake no matter how easy the job is)
Changed brake pads (rim and disc)
Changing cables is coming up on my list

As I know I'm approaching the time where there's a job I'll want to do, I just google 'how to' videos and ask questions on this forum (usually when things go wrong!). There's a LOT of good material out there. That way you can learn techniques and what specialized tools you'll need before starting.

Park Tools has great videos and I like GCN (I really like their video on greasing a headset). There's also many others out there but I find those two have an expansive set of videos. The nice thing about Park Tools for a beginner is they tell you which model Park Tool you'll need for the job (well, it does feel like kind of a marketing thing but if you can get over that, it's helpful when you're trying to get oriented to doing your own work and building up a workshop).