Textbooks for reading only?

There is a thing called Graded Readers which are special books (as in, contain stories and such) geared towards learners, and they start from almost zero knowledge up to almost native level. Those can help you get used to reading as such, but they just contain the stories, you need to do the studying yourself. But you can find lots of grammar information online, and you can look up words in e.g. http://jisho.org so maybe that would be an idea for you. There are some threads about Graded Readers here on the forums, and I think there are also some that you can read for free?
Once you are able to read a little bit, you could also join the Absolute Beginners Book Club // Now reading: Horimiya // Reading Next: Miss Shikimori is not just cute! - they will start their next book in February so maybe you could test the waters with that one as well. The club members help each other with each and any question people may have, and often people also translate story parts to check their understanding.