I recently posted about tomorrow's to a data making workshop at Patchube London. I've been checking out the hardware and making sure that I can program it with my laptop and an FTDI cable.
The Arduino ethernet example sketches include a Web Server which displays the values of the Arduino's analog ports.
I rigged up a breadboard with a potentiometer and connected it to the Arduino Ethernet board.
With 6 years of history and 600,000 users, Arduino and its documentation have been tested and re-tested. Arduino examples just work. Relative newcomers like the Beaglebone are catching up, but the Arduino has set a high standard to aim for.