Been loading for 40+ years and have accumulated several Manuals & Booklets.
Most of my information comes from the Hodgdon Reloading Data Center that is On-Line.
http://data.hodgdon.com/main_menu.asp
As for hardbound manuals, I feel that they should be updated every few years because things change. Don't ask me why or what??
I have found notable variants from one manual to another, of different suppliers and sometimes the same supplier.

My #1 go-to manual is the Hornady 7 th. Edition. Also have the Hornady 3 rd. Edition.
I have a Speer #13 but I don't trust it.

Also have several Lyman Manuals, the latest being the 49 th. Edition. Also have the 45 th., 43 rd., and an older one without a front or back cover. All very handy for reference. I've heard very good reviews on the Lyman, especially from those that cast their own bullets.

Sometimes, different powder company's give out Booklets. I have some from Accurate, Winchester, Hodgdon, DuPont & IMR.
Grey