The following is a hotness ranking of peppers (though far from an exhaustive list) from mildest to hottest, including the jalapeno pepper. You'll see where the jalapeno pepper falls in the overall heat range.
El Paso (Very mild)
Habanero (One of the hottest grown - 30 to 50 times hotter than a jalapeño)
Chili pepper recipes, preserving, gardening and harvesting chili peppers, chili pepper types and much more. The purpose of Chili Pepper Madness is to inspire creative cooking and fun with chile peppers.