Lee, Lyman and Hornady are my favorite sources. Richard Lee promotes his tools but I happen to like many of them so it's a good asset. Lyman has an excellent basic book and I like their more specialized books as well. Steve Hornady makes excellent tools, cases and bullets and happens to write a good manual to show us how to use them. I have other manuals and older versions of some and they all get used on a regular basis.
I'd start with no less than two, preferably three, depending on your area of interest. I did pretty well for my first few years with the RCBS manual but additional manuals give you a much-needed broader perspective when developing specialized loads. Some manuals don't like certain powders or bullet designs but if you have more than one manual you can likely find a good starting point for most any reasonable combination of components.
Life Member NRA, TSRA
Smokeless powder is a passing fad! -Steve Garbe
I hate rude behavior in a man. I won't tolerate it. -Woodrow F. Call Lonesome Dove
My favorite recipes start out with a handful of used wheelweights.