Here is a good, very detailed book on reloading.
"Handloading for Competition: making the target bigger" by Glen D. Zediker
I wish I had read this book 5 years ago.
Other items that you might need or want to upgrade.
Good Digital calipers
Stoney point gauges
?? its tough, as we don't know what you have now.
If some is good and more is better, then too much is just right.
My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives