Hi andreafuyu! In case you haven't seen it, we have a room full of information about publishing: Publishing FAQs and Resources. It does take some time, but you will benefit from doing your own research here, rather than asking people to summarise it quickly for you. You risk missing some useful information because the people who are generously and helpfully replying can't know all the details of your needs.
Have you checked out Lulu? They probably will be closest to what you need and are legit and all.
Are you in China? Selling comic books is more difficult than selling regular novels. In some countries comic books are mostly sold in specialized or independent stores rather than regular bookshops. And to get your comicbook to those specialized or independent stores you need to go there in person. Which, of course, will depend on where in the world you are.
In general, comicbooks published by vanity/hybrid publishers will hardly ever be picked up by bookstores because there is no quality control at publisher level and the bookstore has no chance of knowing what they are getting. They can't read every book in order to decide if it's good, right? Again, you'll need to go around in person, offering your book to them.
There is a "comics" sub forum on AW that might be of some help https://absolutewrite.com/forums/forumdisplay.php?89-Comic-Books-and-Graphic-Novels
I'm not sure there are any Agents who rep comic books, unless your goal is to be published by one of the big comic names, like Marvel.
There are many who are interested in Graphic Novels but don't know if what you have done could be a GN nor if you want to go that route.
My impression (no personal knowledge) is most Comic book artists/authors go the self publishing route. They sell at shows like comic con, on-line and approach comic book stores in hopes they might stock. There are also comic book publishers, this requires submitting and waiting as with other publishers.
True. Thank you very much for enlightening me of it.
I noticed nowadays there are many yaoi or yuri Chinese comic widely spread outside China. However, most of them are webcomics but not publications. I wonder how the traditional bookstore treats with the comicbooks adapted from the webcomics.
If the webcomic can get a publisher behind it one way or another, then they are more than welcome in bookstores and have been for years. The first I remember was Megatokyo, years and years ago by a publisher that's now defunct, but it was available on shelves. Here's an article with a bunch of webcomics and their physical publishers. Image and Dark Horse are the biggest publishers outside of Marvel and DC, and unlike M&DC, they publish a wide variety instead of their own specific lines. There's one coming out next week called Check, Please! that's being published by Macmillan. Basically, in a very long answer: if the webcomic is good, absolutely.