Acquiring basic skills working with visualizing/analyzing large data sets
I like the book Data Analysis with Open Source Tools by Janert. It is a pretty broad survey of data analysis methods, focusing on how to understand the system that produced the data, rather than on sophisticated statistical methods. One caveat: while the mathematics used isn't especially advanced, I do think you will need to be comfortable with mathematical arguments to gain much from the book.
I'm looking for a way to learn to be comfortable with large data sets.  I'm a university student, so everything I do is of "nice" size and complexity.  Working on a research project with a professor this semester, and I've had to visualize relationships between a somewhat large (in my experience) data set.  It was a 15 MB CSV file.
I wrote most of my data wrangling in Python, visualized using GNUPlot.
Are there any accessible books or websites on the subject out there?  Bonus points for using Python, more bonus points for a more "basic" visualization system than relying on gnuplot.  Cairo or something, I suppose.
Looking for something that takes me from data mining, to processing, to visualization.
EDIT:  I'm more looking for something that will teach me the "big ideas".  I can write the code myself, but looking for techniques people use to deal with large data sets.  I mean, my 15 MB is small enough where I can put everything I would ever need into memory and just start crunching.  What do people do to visualize 5 GB data sets?