One of the most rewarding and common garden crops around. Peas prefer cool weather and soil for germination and growing, and can be planted early Spring or Fall for a second crop. Plant peas 1-2" deep, 2-4" apart. Space rows 12-18" apart for dwarf (non-staking) varieties, 4-6' apart for climbers (I plant double rows for climbers so peas grow up both sides of the fence). Get them in quick, and once harvest starts, the more you pick the more vines will set flowers and pods.

Shell peas are varieties where you allow the pods to swell and peas to partially develop. Pods are popped open and fresh peas are "shelled" out for fresh eating or freezing.

Snow peas are harvested before the pods start to swell and the whole pod is eaten.  

Snap peas are the best of both worlds, where the pod and peas swell, but the pod becomes thick and juicy and the whole thing is edible.