Reinstalling the front wheel
Putting the front wheel back on is pretty straightforward, with one exception: the speedometer drive. If you don't have the speedo drive aligned properly with the nubs on the fork, the slightest bit of torque on the axle nut will cause the wheel to be nigh on impossible to move.
First, take careful note of the bits and pieces that come off when you pull out the axle: axle, right-side spacer, speedo drive, washer, crown nut and cotter pin. Reassemble it all in the same order.
The first problem to overcome is to make sure that the speedo drive meshes with the teeth in the wheel. You have to line up the notches in the wheel with the notches on the speedo drive. Get those inner notches lined up, then spin the wheel a tad to line up the notches on the fork and speedo (see below). This parts diagram shows the two pieces that need to fit together (both are circled). The raised portion on the speedo gear (41060) needs to go in the notches on the part on the wheel (41064).
The second problem many people have is related to the rotational position of the speedo drive. Look carefully and you'll see one post on the speedo drive and two on the fork tube. You need to get the speedo drive post in between the two posts on the fork tube. When it's in position, the speedometer cable should go up from the drive approximately parallel to the fork tube. The picture below has one of the tabs on the fork circled. There are two of them, and the raised bump on the speedo housing fits between them.
If you're WAY off, like 20 degrees, you can actually reassemble the wheel usably, because the posts aren't interfering with each other, but it's wrong and will allow a lot of play in the speedo drive. There should be a little (1/8") rotational play, but not much. Once you think you have everything lined up, give the wheel a spin before you put the nut on. That should tell you if everything is in the right place or not.
One other thing: Pay special attention to the lip seal on the speedo drive. It is thin and easy to fold over when installing the front wheel. The result is an annoying squeak at parking lot speed.
Shown below are closeups of a correctly-installed speedo drive housing.