As a longtime proprietor of the use of machine translation to provide rough passthroughs of translation of medias from their source language to english I am perhaps uniquely qualified to give a guide to my tried and true method of translation:
Step 1: Acquire source material:
This is easiest if the source material is directly text, but otherwise this can be counterracted for.
For ebooks, Anna's Archive is the place to go (do check the outoing links at the bottom of the page for external downloads of a far faster speed than the website allows)
For manga, check nyaa.si and then follow outgoing links if no-ones seeding (you might find a dodgy rapidgator link). Also check around to see if you can find translations into languages that might be easier to translate (such as russian, which is relatively common and you might have to check language specific scanlation sites).
For any kind of webtoon i think extract.pics should probably work or you can get browser extensions that allow you to screenshot a whole page (and then you can just split the image up)
Step 1.1: OCR the text (skip this step if you could find an EPUB or some other kind of document with actual copyable text in it)
Since i'm using Arch linux, this is a bit harder than windows, despite the sheer amount of OCR tools for my distro.
I've found KanjiTomo to be the most reliable, and also the slowest. OCRFeeder is okay as well. Normcap should be better than it is it's just kinda buggy.
For online tools, Poricom looks promising but I couldn't get it to work
SnowMTL offers a good rough passthrough quite fast as well
(if you have a PDF file, you'll need to get it converted into images for SnowMTL, Poricom & KamjiTomo, for linux there's a pretty nice application on Flathub called PDF Tricks that lets you do this locally, but otherwise there's a gazillion websites that let you do it
Step 2: Translate the text
For Japanese: DeepL, RomanjiDesu, Jisho (dictionary lookup)
For Russian: Yandex Translate
Step 3: Syntax and Localisation
Localising the text is to me the purest form of translation and something that is oft missed by amateur translators (and MTL). The way to achieve this in the best way possible is to try and find a 'phrasing of best fit' for every syntactical (sentence structure and flow-based), lexical (word-based) and aphorical (proverb/saying-based) difference; with the addition of a translation note explaining your choice of words and its relation to the definition of the original (sometimes you won't even get a particularly close fit and you have to bend the text to your linguistic will, in which case translation notes are definitley in order). Remember, your job as a 'translator' is not just to convey broad meaning (that's what the Machine Translation Software does), but to extrapolate out the inferred meaning of the text, it's linguistic intricacies, to really understand the author's choice of language, and adapt the broad meaning you're fed into something that flows well in English, not just something serviceable (again, that's what the Machine Translation Software does).
Step 4: Editing/Re-Formatting
ebooks: Just use Sigil for Epubs
manga: whatever image editor you use and some comicraft fonts
