Advice for Fixing Up Wooden Wheelbarrows?

I have just purchased 2 small wooden wheelbarrows that are meant for the garden. They've been exposed to the elements for a long time and the wheels are badly split. Should I oil, varnish, paint or what? I would like to use enamel paint on them as they will be in the garden. My main concern is making them sturdy in the elements. Thanks so much for your help!