Stuart,
I (and others) have written some simple example projects on this community, that you can try out:
- Detect radioactivity at home with Mathematica , by MarcoThiel.
- Building a GPS tracker with the Raspberry Pi
- Reading potentiometer values through your Arduino with your Raspberry Pi
- Recording a time series of simple GPIO sensor data
(and so on, you can search for posts under the Raspberry Pi group).
For a fast introduction to the language, you could check out Stephen Wolfram’s introduction.