Apologies in advance if I end up rambling.
tl;dr ebook Japan has a lot of good, free, full volumes of manga.
One resource that I use pretty much every day that I’m surprised more people don’t mention (or at least it feels like it). Is ebook japan, specifically the app.
It was surprising to me how many really popular series end up on limited free, especially considering I only checked it out because I’d heared you could use it to check if something had furigana.
Like right now on they’re limited free section they
have multiple volumes of food wars, haikyuu, and that one horror series on the beginner book club list.
And in the past they’ve had multiple volumes of hunterxhunter, skip beat, and a silent voice (though this might’ve had just one volume, I can’t remember) just to name a few.
Plus with the limited free section you’re on a bit of a time limit (usually about two weeks), which is good motivation to get some reading done.
And they usually add a bunch more stuff every other day or so.
And I haven’t even mentioned the not limited free manga. But this post is already pretty long, so I’ll stop here.