The most interesting things I learned were
- tax information - gotta start saving those receipts!
- what to expect in the hunt for an agent and editor - I knew about the rejection bit :-) but the fact that rejection can take up to a year to arrive was news to me
- how long the whole process takes once you start working with professionals for edits - when you think you're done, you still have a year or two to go!
Overall this provides ammunition for me against those people who said "why don't you just take a two-month sabbatical from work to get this done?". It's a long haul, people. A long haul.