The RMA Woolwich Cadet Registers cover the years 1790 to1793, 1799 to 1805 and 1820 to 1939. Those for the RMC Sandhurst cover 1800 to 1946. Both sets record the name, age, date of entry, commissioning date and corps or regiment joined. Occasionally they can give examination results, information about the father, or in the case of RMA Woolwich, sometimes the school. The subsequent career of the cadet is usually not covered.
The staff registers are more restricted in their time span and what they record. The RMC Staff Register covers 1802 to 1939, the RMC cash books until the early 1950s and the RMA Staff Register covers between 1893 and 193. All can be searched at the link below. Searching is free but records cost £2.99 http://archive.sandhurstcollection.org.uk/