Some books, although good, have misprints that they will stand behind even if you call them (Speer 13, 10mm load data, 3N37, says to load the same charge of powder under two different bullet weights, a charge Viht says is a full 2 grains over max). While the data may be safe, it is erroneous, because either one load is over the maximum, or the other load is way under what a max load should be. That said, I like the Speer manual I got with my kit, but just about any manual should have similar information as far as how to is concerned, at least from what I've seen. I like using the manual that goes with the equipment I am using, and I get my load data elsewhere.
Getting the correct information from the specific bullet makers and/or powder makers you use is more important than any book when it comes to the actual loads. That is why I like Load Books: they have data from several manuals and several manufacturers, both bullets and powder, for one specific round. Hornady, Speer, Nosler, Viht, Hodgdon, etc. My 10mm/.40 book (a two fer one!) for example, has 2667 loads using 68 different bullet designs/weights and 50 different powders. All for about $5 from Midway, just get the calibres you load.