Links to useful soaring weather forecasting and current weather products:

National Weather Service - Hourly Forecast (with mixing height)
Wichita KS Soaring Forecast
GOES Satellite Feed
Weatherstation
Windy.com

Links to glider tracking and task reporting:

WeGlide
OGN Tracking

Links to glider training material:

FAA Glider Flying Handbook
Gliderbooks.com (use code KSA76 for a 50% discount)