Here is a set of online articles that help understand the mathematics behind Agile. We add to these all the time and would like to hear ideas you have for more.
To be honest, you probably know us because of our spreadsheet tools. Thats OK, but now consider training :)
Throughput Forecaster: I want to forecast how long a single feature may take <=== UPDATED (announced on ProductHunt)
Modeling and Simulating Software Development Projects NOTE: Very out of date!
Forecasting using Data NOTE: Medium book on probbilistic forecasting
KanbanSim and ScrumSim Application - just download and unzip, requires Windows (just get a free VM on Amazon or Azure and simulate there)