Well Gorfindle, I really like the map you have there, mainly 'cause it leaves me wondering what is just outsides its area. I love maps that leave you wanting more.
Have some rep and a hearty Welcome to the guild.
You will find many a tutorial on using PS here (all geared to map making ) as well as some on Wilber by its creator Waldernate (I hope the spelling is correct ) so you should be able to find any help that you may need.
Enjoy your time here.