looking for information on identifying different winter squash

They aren't quite interchangeable in terms of taste or keeping qualities, which makes them interesting. A buttercup has a dry, almost chestnutty quality and is a pretty good keeper. Butternuts can be peeled and the flesh is more soft; they keep forever. A delicata has such thin skin that it can be eaten, but these squashes are more perishable. You need a hacksaw to get into a hubbard. I'm trying red kuri for the first time this year. Take a peek at a Fedco catalog (available online) to get a real sense of the variety!

I'm not sure I'd agree that all -- or almost all -- winter squashes are interchangeable: a Butternut is not a Delicata is not a Hubbard is not a Spaghetti squash (and those are simply the ones commonly available in the supermarket -- this total list is MUCH longer. I wouldn't (don't) cook any the same way, nor expect the same results if I use one in place of another...

I love the winter squashes. So much versatility and depth of flavor!

thank you both-!

For practical purposes, almost all of the winter squashes are interchangeable.

Here's a good site:
http://www.thenibble.com/reviews/main/vegetables/squash-glossary.asp