SID, like they say, depends on what you want to know, electronics is essentially the flow of electrons, so if you want to understand that than may i suggest a LEMON clock demo, sounds like you are just hobbying, I think what you are interested in is simple battery reactions and such, so if you want to learn that you will need a gr 10 ish chemistry level, things such as valances and compounds, and "what makes atoms happy(natural flow)"
IF you want to get in to electronics, then get in to electronics(introduction to), you will learn things such as resistances, dielectrics, current flow, learn that first, then after you are familiar with the basic dynamic of it all, you can look deeper in to those things and "what makes em spin",,, such as why copper conducts better than carbon or nitrogen,...