analogous -- colors next to each other on the color wheel (ie red + orange)
complementary -- colors opposite each other on the color wheel (ie red + green)
triadic -- colors equally spaced on the color wheel (red + blue + yellow)
shit i know (coloring is my fav part of drawing i know what im doing ok)
for real tho just read the wiki article on color theory its very useful
DONT USE PURE BLACK (#000000) OR PURE WHITE (#FFFFFF)!!! EVER!!!! ok not never, but use them significantly less! only use them if you need them.
dont use the same color for shading or highlighting -- by default use a color next to it on the color wheel. ie: if you need a highlight for something red, dont use light red. use light yellow. for shadows use purple. but try colors elsewhere on the color wheel too!
another rule of thumb for lighting: use warm colors for highlights and cool ones for shadows.