Short answers, pulled from the story.
The Apollo Lunar Surface Experiments Package contained a Central Station, Passive Seismic Experiment, Active Seismic Experiment, Lunar Surface Magnetometer, Heat Flow Experiment, Solar Wind Spectrometer, and Laser Ranging Retroreflectors. Additional components included the Cold Cathode Ion Gauge, Charged Particle Lunar Environment Experiment, and Dust Detector added on later missions.
Scientists from Massachusetts Institute of Technology, Columbia University, Georgia Tech, Rice University, Stanford University, and Yale University designed the specific instruments. Principal investigators such as Frank Press, George Sutton, Robert Hostetler, C. P. Sonett, Jerry Modisette, J. W. Freeman Jr., Curt Michel, M. Langseth, S. Clark, B. J. O'Brien, R. L. Kovach, and J. S. Watkins led these efforts.
NASA officials ended support operations for all five ALSEP stations on the 30th of September 1977 due to budgetary constraints. Engineers determined that power packs could no longer run both transmitters and other instruments simultaneously by that date.
Astronauts used lanyards and pulleys to open the Scientific Equipment bay doors before removing subpackages with a boom system. The Central Station served as the command center while astronauts manually positioned components like the RTG cask and antennas toward Earth.
Apollo 12 carried a full ALSEP array including the Lunar Surface Magnetometer stored on the first subpackage alongside the Passive Seismic Experiment. Apollo 14 fired thirteen of twenty-two Thumper charges successfully before concerns about mortar deployment prevented firing four remaining explosives.