I am looking into studying some econometrics to get some idea of what economists are doing.
Here are the course materials (both courses and books) that I have found free online on the subject:
http://www.saylor.org/courses/econ203/
http://ocw.mit.edu/courses/economics/14-30-introduction-to-statistical-methods-in-economics-spring-2009/
http://ocw.mit.edu/courses/economics/14-30-introduction-to-statistical-method-in-economics-spring-2006/
http://ocw.mit.edu/courses/economics/14-32-econometrics-spring-2007/
http://ocw.mit.edu/courses/economics/14-382-econometrics-i-spring-2005/
http://opencontent.uct.ac.za/Commerce/Economics/Quantitative-Methods-for-Economics
http://bookboon.com/en/textbooks/economics/econometrics
http://www.ssc.wisc.edu/~bhansen/econometrics/Econometrics.pdf
I'll look at them and decide which one is appropriate. Anyone want to take a dive with me?
What exactly is your background in mathematics, statistics, and/or economics? You should take courses in multivariable calculus, linear algebra, and elementary statistics before diving into econometrics.
That said, econometrics is an EXTREMELY dry subject. You should only take it if you think it'll help your career.
Econometrics can be fun at times. I'm not the only one who has written Valentine's cards using indifference curves, am I?
I didn't look at all your resources, but I would advise against using Bruce Hansen's text book (your last link). It is a PhD level textbook and it is very linear algebra heavy. You will spend all your time just trying to understand the math. You wont get a sense of what it all means or how and when to use the techniques.
If you want a good first pass at econometrics, I recommend Wooldridge's Introductory Econometrics. It is used in undergrad and masters levels econometrics courses and it is pretty self-contained. You really only need a little familiarity with calculus (be able to take partial derivatives) and stats (know what a probability distribution is) to understand everything, but I think you would be fine without even that much. The book has a pretty nice appendix section that covers almost everything you need to know. And if you run into any math you don't understand, just go to Khan Academy.
Honestly, the hardest thing about introductory econometrics is learning how to code. Part of every metrics course is learning how to write code for programs like STATA or R to manipulate and analyse data (I prefer STATA, but R is nice because it is free). If you buy the book, it comes with datasets you will analyze throughout the book. For a lot examples and exercises he gives you the answers so you can see if you are writing the code correctly.
If you want the textbook for free, just google around and I am sure a free pdf will pop-up. If you can't find it, PM me. I have a pdf I can e-mail you.
Ambition is a dream with a V8 engine - Elvis Presley
Thanks!