I think it is a good chioce to read online newspapers, such BBC, VOA, Times, etc, to build your vocabulary as well speaking skilles. 

A lot of times I found that it is difficult to analyze the grammar in some original books, especcially which are written by some famous writers, maybe because they are too focus on their artistry and literariness. 

I give some opinion here, but I do not know how about your English. Maybe your English is good enough to read those original books and you can enjoy those genre or stype related with those famous writer. 

Hi! I'm really happy about this site. I can talk with native speakers and I like to meet new people from all around the world too/as well. I'm having English lessons with a professional teacher and i I also want to try improving my English by my own self (or too and omit also); i I don't mean studing grammar, but reading books, newspapers, and everythinkg on the internet. I want to ask wonder if you can suggest me some English books in that can could be helpful for my language learning. I don't want to reading a too much complicated books, but not even or ones/books for kids (or kids books). I need one ones/books that i could will improve my vocabulary and my conversation capabilities/skills with. Thank you! Great, ending a sentence with too is ok, but, I have included another option with also. Remember to include 'to' such as to meet:)

Personally I like this site a lot http://english-e-books.net/findbook/
You can choose yuor level (from Elementary to Advanced) and pick a book adapted for your level of english. As a cool bonus there are audiobooks attached to the text, so you can read/translate and then listen to what you've been listening to.
Hope it helps :)

Perfect thank you everybody for your help!

Alessandro

P.S. Please Can you correct mistakes in my main comment? : )

There are a lot of books out there. Try this website: https://www.goodreads.com/list/tag/esl