I wrote this up... want to add it to wiki. But I figured I'd let y'all read it and post your comments for anything that might need improving or further explaining before I do it.
Darkfinn's Diapering Guide
So... you've taken your first real step into a larger world. You went out and got your first pack of adult diapers. You got them home, hidden away safely... and now is your chance to try them out. So what do you do?
As you probably know there are many types of diapers out there today. Some are good, others are not so good. Odds are you went down to your local pharmacy and grabbed a pack of whatever they happened to have on hand. Unless you are very lucky what you have falls into the "not so good" category. But that's all right... there are lots of folks who use the locally stocked brands b/c they are generally inexpensive, easy to find, and can be bought by the pack (which is easier to conceal).
Before you begin the fun, take a moment to analyze what you have infront of you. Some diapers are cloth backed, some are plastic... some have four tapes (or velcro), some have six... yours may or may not have leak guards... it may or may not have elastic waist bands.
Now that you know exactly what you've got you can put it on properly. There are many different methods of self-diapering, I will outline the one that works best for me. Start by laying the diaper out flat on the edge of your bed, front (side with no tapes) facing you, unfold the sides and get everything as smooth as possible. Now turn around, spread your legs, and back up until you get to the edge of the bed. Pull the front part of the diaper between your legs and sit down on it. Since you are sitting it should be easy to reach around and pull one side of the diaper up.
If you have a 6-tape diaper start with the center tape. Stick it on a line about level with the top of the diaper's front padding... don't press down too hard... just enough so it will stay. Move to the other side of the diaper and do the same thing. Now that you have two of the tapes attached you can stand up and finish adjusting the diaper for the best possible fit. Do the top tapes first, pulling them so the diaper is snug around your waist, place them just above the middle tapes... then do the bottom ones. Once that is done you can go back and re-stick the center tapes so everything feels good. On plastic diapers (like Depends) the tapes will tear the plastic if you pull too hard... so remember to use a gentle touch.
If you have a 4-tape diaper start with the upper tapes. Get them as snug as possible around your waist, then stand up and move to the lower ones. Again, remember to just stick the tapes lightly the first time, so you can go back and readjust.
If the diapers you got are cloth-covered then you are in luck, as the velcro pads on them are infinitely readjustable, so keep moving them until you get it right. If your diaper is plastic backed 2 or 3 sticks with the tapes is pretty much all they are good for. Either the plastic will tear or they won't stay stuck after that.
AN IMPORTANT NOTE -- Boys... now that you have the diaper on please adjust your "tool" so it is pointing downwards. It may be uncomfortable for a while... but it is for the best as it will allow the diaper to absorb more effectively. If you are "unable" to point it downwards at this very moment... give it 15 mins or so so relax... then do it.
So... congrats... you are now properly diapered now for challenge number two.
You have the diaper on... and you need to go pee...
You would think it was easy to go in a diaper... but it's not. You have had years of toileting engrained into you by society. Your body simply does not think that it's proper to be relieving itself while you still have an item of clothing covering that area. Overcoming this obstacle is something many of us struggle with for a long time... and this is just the first step.
For first-timers the best method is to wait until you REALLY need to go. A little "bladder is not empty" tickle just won't do. Wait until you are full, then proceed into the bathroom like you normally would. Go ahead and pull your pants and underwear down, and assume the normal toilet position (guys: standing, girls: sitting). The objective is to trick your brain into thinking everything is "ok to go" and then you can go. Try to relax, take a few deep breaths and think about going in the toilet like you always would. It may take a minute or two... but you should get success with a little patience. Maybe even try running some water to help move things along. If you don't get anything out... give it 15-20 mins and come back again. Don't forget to flush and wash your hands too! Even though you haven't "used the toilet" it will make anyone outside think that you have. If you've been in there a while... you might want to spray some air freshener too... for added effect.
It will take some time to get consistant results. But once your body is used to it you can move to another position. Girls can try to go while standing, and boys can try to go while sitting. Eventually you will be able to move out of the bathroom and enjoy the true freedom of diapers. The ability to go anytime, anywhere.