Pros
Coworkers have great integrity, are really good at what they do, nice cafeteria, free parking. Offices are good, you have all the tools required to do a professional job, Summer Fridays. Benefits and pay are just "ok". It feels good to be working on educational material rather than making widgets or car parts. The quality of the textbooks is highly regarded in schools and universities, so people respect your experience.
Cons
Scarborough, always layoff so no job security, not a lot of work/life balance. You'll do a lot of overtime and it's difficult to get the time off in lieu as you'll be very busy. However, I also heard of people in departments where they had to pretend to have things to do because they were terrified about being laid off. Every year there are significant lists of people who are fired to keep the company going, and after that, there are the speeches that "now we've got it". But they don't. Partly it's the nature of large publishing companies these days -- and they keep on the marketing and sales staff but the development side has been haemorrhaging for years.