Acquiring basic skills working with visualizing/analyzing large data sets
If you are looking for visualization rather than data mining and analysis, The Visual Display of Quantitative Information by Edward Tufte is considered one of the best books in the field.
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?