I think the main difference is that they update their lists of suggested resources.<br><br>
There were a lot of complaints with later editions that they got rid of third party suggestions for subjects where the authors had written their own guides. So a first edition would be really cool in that you'll have a wider history and reading and writing suggestions.<br><br>
However, the first edition is pretty old at this point, and homeschooling (particularly along the classical model) has advanced in leaps and bounds. So the old suggested resources may be out of date: either no longer in print, or replaced by a better option.<br><br>
I would buy it and read it, but if you go looking for specific curricular resources I would ask either here or at the WTM message board to get the most up to date suggestions. You could also take the book out of the library and jot down any major differences you notice.
I wanted to add that even if you (or anyone else reading this thread) has the most up to date version, imo it's always worth it to ask for advice about curricula either here or at the WTM forum (or at any other pertinent HSing forums). Different things work for different kids, and you can get a lot more useful information from a group of been-there-done-that HSers based on your particular needs than you can from even the best resource guide.<br><br>
So I don't even think that my suggestion to ask around for updated suggestions is a mark against buying the first edition. Maybe you have to be a bit more careful in asking around, just to make sure something isn't out of print or is no longer the best thing out there. But the ladies and gentlemen over at the WTM boards are an AMAZING font of curricular information. They constantly blow me away. Here too there is a ton of good information, but classical education proponents tend to be more of a minority.
Thanks so much! I have the latest edition that I borrowed from the library. I'll hold on to it until my copy arrives to compare. Thanks for the advice to check the WTM boards. <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/smile.gif" style="border:0px solid;" title="smile">