Discovering Statistics with SPSS 2nd edition by Andy Fields? Still usable?

I would probably wait until 2009, depending on how badly you need to use it. I didn't find too much of a difference between SPSS v 15 to SPSS v16 to be honest. If you really need to you could use the 2005 edition, or buy a supplement that explains all of the changes. I have no experience with the text, but I have used the program many many times.