The wheels keep falling off - how to repair?

The axle holding the front wheel to the trucks came out (the bolt that inserts into another bolt apparently unscrewed itself, and the wheel & spacers etc fell out). However, the parts we collected from the road don't appear to make sense together - does anyone have pictures or video showing how to remove and replace the wheels?

Specifically, I need to know what size spacers to order, order of construction, do you need to add LockTite to the bolt, or any other tricks.

I put them back together as well as I could but it didn't look completely right - the wheel was slightly offset to one side (the spaces/washers on either side of the wheel are different lengths!) 2 weeks later the wheel fell off again!

Thanks,

-- Demis