Resources for learning Taiwanese
Most recommended
While there aren't a lot of resources, a few standout books and sites are available for learning Taiwanese Hokkien in English.
Here are some of the best ones i've come across while learning.
Bite Size Taiwanese
Although there really isn't much choice when it comes to podcasts for learning the Taiwanese language, luckily this one is really well made and a joy to listen to. It's easy to tell a lot of planning went into this podcast as lessons are well structured and full of knowledge. There are also extra paid materials that can be bought such as worksheets and a vocabulary book, Short Takes: A Scene-based Taiwanese Vocabulary Builder. I just wish they had continued with a few more seasons.
Taiwanese Made Easier
A fairly well structured set of textbooks along with dialogue and vocabulary recordings, these textbook are great for covering the basics plus a bit further. Each lesson has a theme and the recordings are slow and clear making it perfect for those starting out. There are a total of 5 textbooks and some other supplementary material offered on their site. Best of all it's completely free.
Southern Hokkien: An Introduction (three textbooks) by SOAS/NTU
For a textbook I'd recommend either this one or the Maryknoll textbook written below. Both have good parts and bad parts to them. For these books, I was a bit disappointed that the dialogues have no audio (vocab and grammar examples only). Also the numbered tones instead of tone markers, while are fine early on, become a little distracting later on, especially for those also wanting to learn to read other materials in Taiwanese. I was also hoping for a nicer layout and style for a modern textbook, but found it not that much improved on the very old Maryknoll books. I found the books to be full of great content however with lots of explanations for the learner.
There are also free lessons online from NTU which use the textbook to teach but it's completely taught in Mandarin (no subtitles). If you can understand Mandarin Chinese, you can find the lessons here:NTU Southern Hokkien Videos
Maryknoll Taiwanese
The content in them is great, but often catered more to teaching for Christian preachers and you'll find a lot of vocab related to that. The conversations are still relevant for any learners though and it's only a few words here and there. The books are a little old and can be harder to read for those used to modern publications. The pdf files of the textbooks are available online and you can contact Maryknoll directly to buy audio and printed copies.
Reddit r/ohtaigi Taiwanese subreddit
There's lots of information in this subreddit aimed for learners of Taiwanese.
Learning Taiwanese subreddit
Taiwanese Grammar: A Concise Reference by Philip T. Lin
Don't be fooled by the title, this book is the most in depth guide to Taiwanese grammar you'll find. The book is really well written and not as difficult to read as some grammar books can be. Philip Lin is also one of the co-hosts of Bitesize Taiwanese.
Taikegui, Taiwanese song lyrics
A website with a large collection of song lyrics written in Taiwanese. While some sites often just have the characters only, this one uses POJ too. A great resource for those who like learning through music. taikegui website
Other resources for learning Taiwanese worth a mention
Glossika
Although it offers a nice UI and fun method of learning, I've heard some of the sentences used are not so commonly used and often sound a little strange.
Anki
Not just for Taiwanese, anki is a great flashcard learning app for any language. There are a few flashcard sets (decks) for Taiwanese there. I'd recommend using one with sound files attatched.
Memrise
Similar to anki, memrise is a flashcard learning app/website. There are fewer Taiwanese sets here but the interface is a little nicer.
Spoken Hokkien
There are a couple of textbooks for learning Taiwanese Hokkien in English available to purchase here: Spoken Hokkien.I've never used them though so I cannot vouch for the material. There is also an intermediate one that follows the first textbook.
Intermediate to advanced
For a list of materials focused on studying beyond beginner level, see this list: Learning intermediate to advanced level Taiwanese.