I know HTML and CSS good, but I need tutorials which explain web design in terms of shapes, colors etc. Not just web, but also graphic design. I want to learn which colors are good combination, which fonts to use in some situations, when is it best to use rounded corners, which font size to use in some situations etc. I want to some general rules for website good look and feel.
there are no rules there, just what you want:
if you are making a site for a club of surfers, you might want to take buttons in the shape of a surfboard, but that wouldn't make any sense if you're creating a website for a library.
as for color schemes: dark on light (or vice versa) usually does the trick. for large texts, I would suggest dark text on a light background, it won't hurt the readers eyes as much as flashy colors mixed together.