It's disappointing how many Lambda Calculus "tutorials" and "introductions" are really bad about actually being tutorials or introductions. It reminds me of the book for my undergrad class in partial differential equations. The book was thin, concise, and to the point. I'm sure it was readily understandable...to the professor who selected it. To the students, it was completely dense and incomprehensible. Too many of the Lambda Calculus tutorials are like that. Specifically, they too often use symbology and terminology without explaining it. Hint: if I understood it, I wouldn't be looking for an introduction to the material.
Happily the first two links from my last article are well done, even if a bit limited in scope. For a new student, I would recommend starting with them and then following up with this paper. It is clearly the most newbie-friendly of any material I have found that treats the subject with any depth (though even that paper is not perfect in this regard). For the new student, my recommendation would be to read these three pieces, in the order in which they are linked here.