Can anyone direct me to some of the best sources for teaching dealing seconds? Thanks.

Second to None from simon lovell.

Highly recommended

Here are a few more:

* Jason England has a couple good tutorials on Theory 11
* Expert Card Technique by Hugard and Braue teaches both push-off and strike seconds
* It's in Expert at the Card Table by S. W. Erdnase
* Ed Marlo's Revolutionary Card Technique ("Seconds, Centers and Bottoms" in particular) has a handful of second deals
* Further Inner Secrets of Card Magic by Dai Vernon has some second deals
* If you happen to have Steve Forte's Gambling Sleight of Hand yet still don't deal seconds, there is good work there
* Tarbell Course in Magic - Volume 2 has a few
* I hear there is a DVD where Martin Nash teaches seconds, "The award winning card magic of Martin Nash" the charming cheat vol.#5
* Also by Martin Nash, Ever So Sleightly has a one-handed second, Any Second Now has a strike Second, and Sleight Unseen has a few. I hear the Nash Trilogy is great but have been looking for them for years so good luck finding them.