Peas - can be planted as soon as the soil can be worked, until May 1, planting them every 2 weeks.  They should be planted 1" deep, 1-2" apart, in rows 12-24" apart.
 
Lettuce-
Plant 1/4-1/2" deep, rows 12-18" apart, final spacing of plants 8-12" apart.  Plant in 2 week intervals.
 
Radishes-
Plant seeds 1/2-1" deep, rows 10-12" apart, thin plants to 1-2" apart.  Plant in 10 day intervals.  Plant again in early September for fall harvest.
 
Spinach-
Plant seeds 1/2-1" deep, rows 12" apart, thin plants to 3" apart.  Plant in 2 week intervals.
 
