This A5 sheet has common symbols, some overprint symbols and also uncrossable symbols.
Whilst it is not a complete list of sprint map symbols, it should serve as a good first introduction.
It was designed for use by newcomers on the West Cambridge Site, but could easily be used elsewhere.
This A5 sheet has a list of the techniques needed for orienteering at each level of technical difficulty.
There are also others such as relocation which could be introduced at any level.