I'm in the process of teaching myself to read music again, but for keys this time. Everything I learned for cello seems to have dropped from my brain, couldn't remember a single note on the staff. However, I found this handy tool and so far it's been very useful indeed - my treble cleff is pretty good now and the bass cleff is coming on slowly (no idea why I'm finding treble cleff easier to remember!).
[url="http://www.emusictheory.com/practice/pianoKeys.html"]http://www.emusictheory.com/practice/pianoKeys.html[/url]
It basically flashes up a note, and you then have to click the corresponding piano key. On the same website there are similar tools that omit the keyboard and replace with note names, in case you're not familiar with the notes on the piano.