I’m new to functional programming, and I’m learning Scheme in one of my classes. I’ve been through several countless guides, including the top search results for “scheme tutorial”, but even those can’t explain commands like “lambda”, “let”, “let*”, “let-rec” in a suitable, understandable, manner. Here’s a list of Scheme guides that really brought my understanding together:

”An Introduction to Scheme and its Implementation”

http://www.federated.com/~jim/schintro-v14/schintro_toc.html

This person has written this online book on scheme, and I found it to be the best one compared to “Teach yourself scheme in fixnum days”, or the online tutorial by Candolin. The ASCII pictorial representations of scheme concepts are extremely useful to a visual person like I am, and it has many examples for students to follow. This guide really helped me learn let, let*, let-rec; the visual examples for it are AWESOME.

“Got Closures? Have OO”

http://debasishg.blogspot.com/2007/09/got-closures-have-oo.html

I found this while trying to find material on closures. It helped give me a sense of how scheme can be adapted into an object orientated sense complete with inheritance. It also gave me some clarity on how the let and lambda forms work.

“Fabulous Adventures In Coding”

http://blogs.msdn.com/ericlippert/archive/2003/09/17/53028.aspx

This MSDN article really paved the way for me in terms of understanding how closures work. The example is in Javascript, but it’s still useful for scheme.
I hope this small post will help functional programmers as well, as this is the result of my Scheme soul searching for weeks on the internet.