I'm pretty computer illiterate myself, but we do learn by doing, and you'll be surprised what you pick up once you dig into it.
Once you have the mission editor open you need to find the Ubisoft folder. If you use Windows XP it should be under Program Files. If you're using Vista or Win7 I'm not sure where it will be. Someone who has those will have to tell you.
Either way, once you are in Ubisoft open Silent Hunter III, then Data. Campaigns should be the third folder down. You will then see Campaign LND, which controls all the land units, Campaign RND, which controls all the Random units such as convoys, and Campaign SCR, which controls all the scripted units, which includes the ships in the harbors and all the historical movements and battles, which of course includes the task forces with the battleships.
It will look pretty daunting at first, as there are thousands of items on the map, but you'll get used to it after awhile.
