Matthew94 said:
What language are you looking to learn?
This, obviously. Unless your friend wants to write machine code by hand (i.e. really freakin' hard and time consuming) he would be coding in some language or another.
Java seems popular-ish. And the official
Sun[footnote]RIP

[/footnote] Oracle [http://docs.oracle.com/javase/tutorial/] pages are a really good source to learn Java stuff. A friend of mine once recommended me
Thinking in Java as a good book. Although I don't know how beginner friendly it is. Also, I'd suggest myself that he installs BlueJ [http://www.bluej.org/] to write Java in for the beginning. It's a teaching tool specifically for Java and Object Oriented (i.e. a really big thing) software. There are stuff like Java2D and Java3D to do with graphics and games but leave those off for a while. I hear they can be a pain in the ass.
C and C++ are also popular for coding in. I think C++ would be the more appropriate for games. There are [http://www.cplusplus.com/doc/tutorial/] free [http://www.cprogramming.com/tutorial.html] tutorials [http://www.learncpp.com/] online. Lots of them. Probably a bunch of books, as well. I still can't decide if C++ is harder or easier for beginners than Java. But at least one would be really useful...
...partly because of C# (pronounced "see sharp"). As the name suggests, it tries to be close to C/C++ but the syntax is really similar to Java. I've heard it described as "broken Java", and I might agree but I have never really coded any C# - I have seen other people's code though and helped them with it. I only used my Java knowledge to do that. Anyway, C# is used for Xbox games, as far as I'm aware. And
XNA Game Studio hence uses C# (also, as far as I'm aware).
Python is always a good language to learn. Need not be right now, but it's really useful, if you ask me. I really liked Dive Into Python [http://www.diveintopython.net/] which is also free. But now when I googled it, I found Dive Into Python 3 [http://diveintopython3.ep.io/] which is supposed to be the new revision of the book. I literally juust stumbled upon that one, so I don't know much. If it really is the book, it will be even more useful than the other one.
EDIT: I'll just add this link about AI [http://www.ai-junkie.com/] here. It might be useful to somebody. I was digging through my bookmarks and I found it. A friend of mine who is into AI gave it to me and I value his judgement. But I don't know if it's suitable for beginners, I haven't taken a look at it myself.