Resources

Wikipedia on O-Scale trains: http://en.wikipedia.org/wiki/O_scale

Lionel Trains: www.lionel.com

Shifrin: Not a pretty page, but great info http://www.shifrin.net/trains/History/history.htm

An Awesome List of Reference Material on O-scale trains: http://oak.cats.ohiou.edu/~mcfadden/toy_train_links.htm#refs

If you're near the U. Of Wisconsin in April, here's an event you might consider:
https://www.uwosh.edu/llce/conted/lir/events/model-trains-beyond-christmas