Mendel is great science, great statistics and a good puzzle. There are many intriguing features of his work, and it is instructive and enjoyable attempting to come to terms with them.
What was his aim? What was special about peas? What was special about Mendel?
Mendel was not the first to experiment in the way he did with peas. He was probably not the first to get the results he got, but he seems to have been the first to have noticed this regularity, to have theorized concerning it, to have tested his theory, and to have gone on to do more.
There are many readily available English translations of Mendel's paper: Stern and Sherwood's book includes a number of related documents ; Fisher's has a few marginal comments, which supplement and update his famous 1936 paper; while the most recent by Corcos and Monaghan has many useful botanical remarks.