I found these for you and I hope it helps:
Magic Wands: How to make them
http://naturalmagickshop.com/articles/wands.html
Magical Properties of wood
http://goldentreewands.com/magicpropertiesofwood.htm
Sorry but I can't help you more right now. I'm doing my research work and I need to finish it on time. Anyway, good luck with your wand
If you cannot find a suitable wood for you. Please tell me what trees do you have around, I'll try to explain it further for you..
Oh, and regarding the shapes and sizes, choose anything that appeals to you.

Some remove the bark, some polish it, and some just leave it as it is. And some put stuffs that may represent the elements, or maybe four elements. It's up to you
Mine was given to me by a friend, she put feathers, beads, crystal and a pentacle (she got it from her earrings)

I'll post the pic when i have enough time