Reddit mentions of The Path to Bodhidharma: The Teachings of Shodo Harada Roshi (Tuttle Library of Enlightenment)

This site has a bunch of information on how to do zazen: http://antaiji.org/en/新温泉町移住定住プロモーション-l-a-zenmonki-2/

And if you're looking for books with instructions on how to do zazen, there is:

https://www.amazon.com/Zen-Training-Philosophy-Shambhala-Classics/dp/1590302834/ref=sr_1_1?keywords=zen+training&qid=1549654890&sr=8-1

https://www.amazon.com/Everyday-Zen-Love-Work-Plus/dp/0061285897/ref=sr_1_1?keywords=charlotte+joko+beck&qid=1549654919&sr=8-1

https://www.amazon.com/Nothing-Special-Charlotte-J-Beck/dp/0062511173/ref=sr_1_2?keywords=charlotte+joko+beck&qid=1549654919&sr=8-2

https://www.amazon.com/Path-Bodhidharma-Teachings-Library-Enlightenment/dp/0804832161/ref=sr_1_2?keywords=shodo+harada+roshi&qid=1549654938&sr=8-2

If you're doing zazen on your own, you don't have to necessarily do any kind of ritual before it, only if you choose to do so.

And just ignore the crazy people that compulsively post lies and bullshit on this subreddit.

You can go to a buddhist community that has meditation as a practice and learn there. Also, there are a bunch of books that teach different kinds of meditations, and some of them go into detail on how to meditate. For instance, these ones:

[zen training] (https://www.amazon.com/Zen-Training-Philosophy-Shambhala-Classics/dp/1590302834/ref=sr_1_1?ie=UTF8&qid=1535777895&sr=8-1&keywords=zen+training) , [the path to bodhidharma] (https://www.amazon.com/Path-Bodhidharma-Teachings-Library-Enlightenment/dp/0804832161/ref=sr_1_1?ie=UTF8&qid=1535777933&sr=8-1&keywords=the+path+to+bodhidharma) , [everyday zen] (https://www.amazon.com/Everyday-Zen-Love-Work-Plus/dp/0061285897/ref=sr_1_1?ie=UTF8&qid=1535828798&sr=8-1&keywords=everyday+zen) , [nothing special] (https://www.amazon.com/Nothing-Special-Charlotte-J-Beck/dp/0062511173/ref=sr_1_1?ie=UTF8&qid=1535778035&sr=8-1&keywords=nothing+special) , [the three pillars of zen] (https://www.amazon.com/Three-Pillars-Zen-Teaching-Enlightenment/dp/0385260938/ref=sr_1_1?ie=UTF8&qid=1536631531&sr=8-1&keywords=the+three+pillars+of+zen) and these ones which are free : [the 7th world of chan buddhism] (http://zbohy.zatma.org/common/downloads/SeventhWorldOfChanBuddhism.pdf) and [Mindfulness in Plain English] (http://www.vipassana.com/meditation/mindfulness_in_plain_english.php) all have instructions on how to do one or more types of meditations.

You can also find information on the web, like here: https://zmm.org/teachings-and-training/meditation-instructions/ and http://antaiji.org/archives/eng/okumura-zazen.shtml

Or on youtube, like here: https://www.youtube.com/watch?v=kLwVt6Wlqeg , https://www.youtube.com/watch?v=bk7JRHNX19A , and https://www.youtube.com/watch?v=lGzE6BQb1xY .

There's also the topics of recommended links and books of this subreddit:

https://www.reddit.com/r/Meditation/comments/2ixjf6/meddits_online_recommendations/ ; https://www.reddit.com/r/Meditation/comments/2ixjq7/meddits_book_recommendations/

My favorite books about buddhism and meditation are:

[zen training] (https://www.amazon.com/Zen-Training-Philosophy-Shambhala-Classics/dp/1590302834/ref=sr_1_1?keywords=zen+training&qid=1565793019&s=gateway&sr=8-1) ,
nothing special
, everyday zen - love and work , [the path to bodhidharma] (https://www.amazon.com/Path-Bodhidharma-Teachings-Library-Enlightenment/dp/0804832161/ref=sr_1_1?keywords=the+path+to+bodhidharma&qid=1565793271&s=gateway&sr=8-1) , and this one is a free e-book : [the 7th world of chan buddhism] (https://zbohy.zatma.org/common/downloads/SeventhWorldOfChanBuddhism.pdf)

Also, if you're interested in buddhism, visiting a temple if there is one near you and learning there provided you find it worthwhile is another way to learn and practice buddhism.