libraries

hello. I noticed that on a lot of sample programs that are in some of the tutorials that there are some libraries that are included. I have had trouble finding some of these libraries that people have created and am wondering if there is any one place they are located?

It just confuses me why people would use a program as a tutorial and not include the library they used?

For example, some of the PWM tutorials with variable frequency that use some asembly code have special libraries and yet the library files are not included???

Please forgive me if there is something obvious i am missing- I am very new to this, but do have some background in C++.

Also is there somewhere i can find some of the other commands that are used with arduino? I downloaded a very basic programming notebook, but i know that cannot be all the commands that can be used......

any books for learning anyone here would recommend? I would like to advance my skills, but browsing through all the webpages is tiring and not as good as having a book beside me to develop from and learn from.

I dont want to take the easy way out and buy flowcode either.

Thanks in advance for any help

Some one here put this together, maybe this will answer part of your questions
http://www.crossroadsfencing.com/ArduinoLanguageReference.pdf
(right click, save target as, maybe rename to .pdf)
There have been cheatsheets too
http://www.crossroadsfencing.com/Arduino cheat sheet v02c.pdf

A lot of the libraries are found in the IDE now:
Sketch:Import Libraries

Thanks crossroads. that is exactly what I needed.

Most helpful you are! Im glad we have people like you here on the Arduino forums. Otherwise newbies like me would be lost in the dark.......

"Otherwise newbies like me would be lost in the dark......."

Well, that's what all these LED projects are for 8)