I usually watch for when a new edition comes out, and watch for close outs on the old one. If a powder is not listed, I use the Hodgdon.com site for data. I always recommend at least one book for a beginner. Books from Hornady, Lyman and Lee have a lot of good instruction on the loading process as well as powder charge weights and dimensions. The latest data is generally found on the internet, but I usually don't start using a new powder just because it is new. My newest manual is a 4 uear old Hornady, and I still have an old Black and white photo Speer from about 35 years ago that is mostly for kicks. Most powders on the market today were not even there, and it does not have quite a few of todays common cartridges.
I've used Hornday, Lyman, and Lee. all are ok.
I think Nosler (and maybe Sierra) also publish good reloading manuals.
My public library has the Hornday on hand, so I bought the Lee manual, and can borrow the Lyman from a friend.