If your referring to a good instructional manual, I like Speer and Lyman. Speer is great though and really addresses the process of reloading in easy to understand terminology and steps.
As for data, I use the online sources a lot, Alliant & Hodgdon mostly. But I also buy a lot of Lyman books, the one's that address a various range of cartridges. They have some that contain data for cartridges that use a specific bullet calibers such as .224" would contain data for 22-250, .223, and such, then a book for .243" projectile cartridges, like 6mm rem, .243 for example.
I also have a bunch of "One Caliber, One Book" data books. But you have to be careful with this line of books, cause they aren't always up to date. But you can't really have too many books, IMHO.
GS