Yamaha Digital Music World has great articles and downloadable software for taking advantage of Yamaha XG-enabled instruments (like my new piano). I hastily purchased Cakewalk Home Studio 2002 before I discovered XGWorks 3.0, Yamaha's sequencing software with special functionality for XG instruments (which Cakewalk doesn't have). CHS2002 is also something of a mess, user-interface-wise, and XGWorks looks much cleaner. XGWorks even includes acoustic audio recording and syncing, the feature that caused me to jump at Cakewalk in the first place.

Also: XGWorks Yahoo! groups.