Full sun is preferred but part shade is OK. Plant the bulbs as deep as recommended - a rough rule of thumb is 2x the diameter of the bulb or 3-4" for small bulbs, 4-6" or more for larger bulbs. Some of the "stem" (actually just the emerging bulb 'shoot') may be under the soil but this is not a concern and proper planting depth is the overriding issue. And make sure they are located in very well-draining soil.

Got it,thanks Gardengal48