All of May’s full-length novels are standalones and can be read in any order. However, if you want to get the full series experience and/or read them in order of the plot timeline, here’s a list that should help.
The Way Home series:
The Easy Way
The Long Way
The Right Way
The Love In O’Leary series (includes the Love In O’Leary novellas):
The Date
The Fall
The Gift
The Note
The Secret
The World
The Fire
The Night
The Castle
The Light
The Whispering Key series:
Off Plan
Unicorns Forever
On The Run
Off Key
The Sunday Brothers series:
Pick Me
Pick One
Hand Picked
Cherry Picked
Bone to Pick
The Licking Thicket series co-written with Lucy Lennox:
The Licking Thicket: Horn of Glory series co-written with Lucy Lennox:
The Honeybridge Series series co-written with Lucy Lennox: