I haven't painted in a couple of years. I initially worked in oils, but got tired of the stink and the mess, so I went on to watercolors. Much easier medium to stop and come back to if need be, and cleanup is also much easier.
Anyway, you best bet would be to just go to your local library or book store and browse through. I know that colors in oil react so much differently then in watercolor, even if they have the same name. So, you'd be best to find a book catering to mostly acrylic, although acrylic color probably reacts closer to oils.
Theoretically, you should be able to produce any color from just the three primary colors...red, blue and yellow. But, you need the colors to be pretty pure. For example, cobalt blue is a much purer blue then ultramarine (which has a red tinge), or thalo blue (which has a greenish tinge). At least that's the way they appear in watercolors. I've done paintings using just the three primarys, and it is a good way to see how colors mix.
I read many books on watercolor and color mixing, and it is good to get you started, as there will always be good hints that will shorten the learning curve, but there is no substitute for a lot of trial and error. After awhile (it took me a couple of years), color mixing will become almost intuitive with very little thought required. You'll also find that your palette will shrink. What will remain is a core of trusted colors that can and will always give you what you want, with all the other nifty colors that you bought winding up in the trash.
Boy, I need to get back to painting. I loved doing it, but other stuff interfered and ate up my time. Now I've got that time again. You've inspired me to clean out what we used to call the paint room and go buy some paper and new paint.