If you liked Dirr’s “Manual of Woody Landscape Plants”than you will like the “Manual of Herbaceous Ornamental Plants” by Stil. It is laid out the same and is almost identical(It is the equivalent of Dirr’s book in the herbaceous world; annuals, bulbs, etc too). Not a lot of color photos just like Dirr’s book, but really an exhaustive reference that is valuable to have at your desk.
I also have some local books that has a local take on perennials check your state Horticultural Society.