Corrected a few links.

free-programming-books.md

@@ -515,15 +515,15 @@
 * [Byte of Python](http://www.swaroopch.com/notes/Python)
 * [Data Structures and Algorithms in Python](http://www.brpreiss.com/books/opus7/html/book.html)
 * [Dive into Python](http://www.diveintopython.net/)
-* [Dive into Python 3](http://diveintopython3.ep.io/)
+* [Dive into Python 3](http://getpython3.com/diveintopython3/)
 * [The Django Book](http://djangobook.com/)
 * [How to Think Like a Computer Scientist: Learning with Python](http://www.greenteapress.com/thinkpython/thinkCSpy/)
-* [Invent Your Own Computer Games With Python](http://inventwithpython.com/)
-* [Learn Python The Hard Way](http://learnpythonthehardway.org)
+* [Invent Your Own Computer Games With Python](http://inventwithpython.com/chapters/)
+* [Learn Python The Hard Way](http://learnpythonthehardway.org/book/)
 * [Natural Language Processing with Python](http://www.nltk.org/book)
 * [Python Bibliotheca](http://openbookproject.net/pybiblio/)
 * [Python for Fun](http://www.openbookproject.net/py4fun/)
-* [Snake Wrangling For Kids](http://www.briggs.net.nz/log/writing/snake-wrangling-for-kids/)
+* [Snake Wrangling For Kids](http://www.briggs.net.nz/snake-wrangling-for-kids.html)
 * [Think Python](http://www.greenteapress.com/thinkpython/thinkpython.pdf) (PDF)
 * [Thinking in Python](http://www.mindview.net/Books/TIPython/)