How to learn spam email detection?
First of all check this carefully. You'll find a simple dataset and some papers to review.

BUT as you want to start a simple learning project I recommend to not going through papers (which are obviously not basic) but try to build your own bayesian learner which is not so difficult.

I personally suggest Andrew Moore's lecture slides on Probabilistic Graphical Models which are freely available and you can learn from them simply and step by step.

If you need more detailed help just comment on this answer and I'll be glad to help :)

Enjoy baysian learning!