Assorted recs for new accounts:

Bots that will interact with you:
@glitchbot — a bot that glitches photos in posts where you @ mention it

@godtributes will reply to public posts you make suggesting appropriate tributes for various niche gods

@alt_text — reminds you if you’ve forgotten to describe your images

Hashtags:
#cats (cats)
#florespondence (any flora but mostly flowers)
#sporespondence (mushrooms!)

Bots that will not interact with you:
@quasihaiku and @poem_exe — haiku bots (by oulipo's lipogrammatic constraints, quasi avoids latin’s fifth glyph)

@pomological random images from the pomological watercolor collection in the usda's national agricultural library

Find accounts by topic on the trunk: https://communitywiki.org/trunk

Fedi Guides:
Changeling’s Guide to Mastodon for screen Reader Users (what you'd expect from the title): https://www.starshipchangeling.net/mastodon/

A futuristic Mastodon introduction for 2021 (more a cultural guide than technical, decent overview of CWs & commonly used abbreviations): https://wordsmith.social/elilla/a-futuristic-mastodon-introduction-for-2021