The convention is that one puts on arrmour from the bottom up, left to right. The exception is that armoured foot gear — as opposed to normal straw sandals — must be donned after the suneate are on.
This means that once you’ve put on your under-armour togs, you start with your suneate. If you are insane enough to have a pair of kôgake, put them on as well. I would recommend kegutsu for combat, however. Just because.
Next comes the haidate, with the support cord if you don’t have a frog on the dô to help hold it up.
If your kote are the type that attach to your watagami with frogs, don’t put them on yet. If, however, your kote are the type that tie across your body or attach to each other, put them on now.
If you wear any under-armour, such as a manchira or wakibiki, put them on.
The dô is next. Fasten your armour!
If your kote secure to the watagami with frogs, put them on now.
If you don’t wear sode, you can skip to the next paragraph. If you do wear sode and went with the single-pair-of-frogs-on-the-watagami option (described in the chapter “Making a Dô”), you have to slip the kote frogs through the loop in the sode frogs before putting the kote on; then you fasten the kote frogs to the watagami. Otherwise, with the double-pair-of-frogs-on-the-watagami option, you just fasten the sode’s frogs to the watagami normally.
Put on your neck armour. (If your neck armour lies flat, you may want to put it on before the dô in the interests of comfort. This is an option for you.)
Put on your face armour if you wear it.
The last key bit of armour is your kabuto. Put it on and tie the cords tightly, securing your face armour in place and leaving no jiggle with the helmet.
If you want, you can also wear a sashimono, although I don’t think most marshalls will be very accepting of them on the field. Nonetheless, many people have fought with them, using fiberglass rods (like bicycle flag poles) as the bannerpole and attaching 1 1/4" diameter wooden balls at the end to make sure they don’t get into eyeslots.
Take your uwa obi (a sash about 6" by 10') and wrap it around your waist several times and tie it in front, tucking any ends back under the wrapped sash. It is through this that you will thrust your wakizashi, tantô, fan, katana, etc. Traditionally, uwa obi are white. In the SCA, that might cause you some problems unless you’re one of those entitled to wear white things around your waist. You can also use black, but I recommend a neutral beige as a decent compromise.
You’re now dressed. Go on, take the field, and show the barbarians a thing or two!