Twitch! Watching (specially micro/low/mid stakes) pros like Kevin Martin/Jamie Staples has improved my game.
Also Jeff Gross.
For entertainment, Tonkaaaap & Lex. They are obviously playing at high/really high stakes so applying their strategies for a micro/low level player like me is probably not a great idea but it's still great learning from their thought process.
If you can't watch live Twitch streams, watch their highlights on YouTube (obviously edited with mostly the important
hands).
As far as coaching goes, after my research, it's down to upswingpoker (by Ryan Fee & Doug Polk) and Raise Your Edge (By bencb789). Upswingpoker has a lot of free content (blogs and articles) and I have felt they have improved my game. Raise Your Edge on the other hand has a great YouTube channel with live plays by bencb789 and tournament breakdowns.
Thing is, the premium content/coaching/subscription on both those coaching sites are expensive. Upswingpoker's Lab is reasonable ($49 a month), but the course I want (the tournament master class by Pratish Badiga) is almost $700. Raise your edge offers two variants at $700 & $1200.
My plan is to sign up for one of those once I run my roll up to $5000+.
For now, Twitch, YouTube, upswingpoker and of course cardschat community.