Hello! Here is some information that might be useful to you:
^ This is an overview of house hold worship. Labrys is a recon group.
Greek and Roman Necromancy by Daniel Ogden.
This book isn't specifically on Hekate, but it does look at a tradition which she was involved in.
The Goddess Hekate edited by Stephen Ronan.
You may be able to find a pdf. This is a closer look at the goddess in a historical context.
Hekate: Liminial Rites by David Rankine.
It's an overview of the goddess in her roles of mythology, art, household worship, and other places like the Greek Magical Papyri and Chaldean Oracles.
This is a small booklet, and I mean small, with information about Hekate and a few prayers. Hellfurian is a Hellenic Witch, so he presents his view on the goddess in the booklet. I would suggest searching his tag on tubmblr if you do not want to buy the booklet. Also on the Vodou Store, there are labels for candles, plaques, and prayer cards to Hekate.
And then of course there is theoi.com. Theoi should have information about Hekate in mythology and cults of her's for free. Other primary sources, which may be on Theoi, are the Argonautica, Homeric Hymn to Demeter, Metamorphosis (The story of Athena and the Spider) and Theogony. Those are primary sources in which Hekate or her priestess is mentioned.
And finally, http://tinyurl.com/jpmzc5o
This is another view of Hekate from the perspective of another Hellenic Witch.