I've been placing random 10uF Caps on the 7805 regulator and am uncertain wether I should be using Tantalum, Ceramic, or Electrolytic caps on the 7805 to act as filters for the 12V to 5V reduction via the 7805. Also what capacitance should I use if 10uF is incorrect for filtering
I really don't think it matters very much - I simply stick 1uF multilayer ceramics on the input and output, as I have plenty of them. Previously I used to use small electrolytics, 10uF or so. It's not for filtering, it's to prevent oscillation.