Sources for Don Quixote consist of the Castilian unique Amadis de Gaula, which had actually enjoyed fantastic appeal throughout the 16th century. Another prominent source, which Cervantes evidently admires more, is Tirant lo Blanch, which the priest describes in Chapter VI of Quixote as “the best book on the planet.” (Nevertheless, the sense in which it was “finest” is much debated amongst scholars. The passage is called since the 19th century “the most hard passage of Don Quixote“.).
The scene of the book burning gives us an excellent list of Cervantes’ likes and dislikes about literature.
Cervantes makes a variety of referrals to the Italian poem Orlando furioso. In chapter 10 of the first part of the unique, Don Quixote says he needs to take the magical helmet of Mambrino, an episode from Canto I of Orlando, and itself a reference to Matteo Maria Boiardo’s Orlando innamorato.  The inserted story in chapter 33 of Part four of the First Part is a retelling of a tale from Canto 43 of Orlando, relating to a male who checks the fidelity of his wife. 
Another crucial source appears to have been Apuleius’s The Golden Ass, among the earliest known books, a picaresque from late classical antiquity. The wineskins episode near completion of the inserted tale “The Curious Impertinent” in chapter 35 of the first part of Don Quixote is a clear reference to Apuleius, and current scholarship recommends that the ethical viewpoint and the basic trajectory of Apuleius’s novel are essential to Cervantes’ program.  Likewise, a number of both Sancho’s adventures in Part II and proverbs throughout are drawn from popular Spanish and Italian folklore.
Cervantes’ experiences as a galley servant in Algiers also influenced Quixote.
Spurious 2nd Part by Avellaneda
It is not particular when Cervantes started writing Sequel of Don Quixote, but he had most likely not proceeded much further than Chapter LIX by late July 1614. About September, however, a spurious Part Two, entitled Second Volume of the Ingenious Gentleman Don Quixote of La Mancha: by the Licenciado (doctorate) Alonso Fernández de Avellaneda, of Tordesillas, was published in Tarragona by an unknown Aragonese who was an admirer of Lope de Vega, competitor of Cervantes.  It was translated into English by William Augustus Yardley, Esquire in two volumes in 1784.
Some modern-day scholars suggest that Don Quixote’s imaginary encounter with Avellaneda in Chapter 59 of Part II must not be taken as the date that Cervantes experienced it, which might have been much previously.
Avellaneda’s identity has actually been the topic of numerous theories, however there is no agreement as to who he was. In its prologue, the author gratuitously insulted Cervantes, who not surprisingly took offense and responded; the last half of Chapter LIX and the majority of the following chapters of Cervantes’ Segunda Parte lend some insight into the results upon him; Cervantes handles to operate in some subtle digs at Avellaneda’s own work, and in his beginning to Part II, comes extremely close to criticizing Avellaneda straight.
In his introduction to The Portable Cervantes, Samuel Putnam, a kept in mind translator of Cervantes’ novel, calls Avellaneda’s version “among the most disgraceful efficiencies in history”. 
The second part of Cervantes’ Don Quixote, finished as a direct result of the Avellaneda book, has happened concerned by some literary critics  as superior to the first part, due to the fact that of its greater depth of characterization, its conversations, mostly in between Quixote and Sancho, on diverse topics, and its philosophical insights.
Don Quixote, Part One consists of a variety of stories which do not directly involve the 2 primary characters, however which are narrated by a few of the picaresque figures encountered by the Don and Sancho throughout their travels. The longest and best known of these is “El Curioso Impertinente” (the impertinently curious male), discovered in Part One, Book Four. This story, read to a group of tourists at an inn, informs of a Florentine nobleman, Anselmo, who becomes obsessed with testing his spouse’s fidelity, and talks his buddy Lothario into attempting to seduce her, with devastating results for all.
In Part Two, the author acknowledges the criticism of his digressions in Part One and promises to concentrate the story on the central characters (although at one point he regrets that his narrative muse has been constrained in this manner). Nevertheless, “Sequel” includes several back narratives related by peripheral characters.
A number of abridged editions have actually been released which delete some or all of the additional tales in order to concentrate on the central narrative.