Lol best advise for doing arch by hand is DON'T!!!!!
But..........if you insist.........
1: open your map and make sure that show dig sites is checked.
2: right click map to see entire continent that you want to farm.
3: you will see 4-5 shovel icons spread out across the map in different zones. Click on the zone closest to you and you will see a red area marked out. That is a dig site.
4: fly to it and when you are inside the boundaries use the survey button from your professions tab.
5: a little spy glass looking thing will show up on a stand. The direction that it points is the direction you need to travel in to get closer.
6: a light will be flashing on the "pointer" red means get on your mount and fly more cause your way off yellow means your in the general area and green means run 10-15 yards and survey again cause your close. Just keep surveying till the pointer doesn't show up and the fragment will be there.
7: on your arch tab you can solve when you have enough fragments.
Again don't do it by hand. It slow boring and will take a LONG time to even get junk.