In an introductory note to this chapter, the Kitzur Shulchan Aruch writes that most Jews are already familiar with the prohibited labors of Shabbos and that he is only addressing common situations with which people may not be familiar. Clearly, the laws of Shabbos constitute an area requiring much greater study than this email alone will allow.
80:23 One may not salt a large quantity of cooked beans or peas on Shabbos because the salt will cause them to soften. This is prohibited even for immediate use.
80:24 Lettuce, cucumbers, and salads made from such things as onions may be salted immediately prior to a meal because one immediately adds the oil and vinegar, which lessens the impact of the salt. One may not salt these things and then leave them for later.