Do you plan to use the Historical Search Room (of what was formerly the National Archives of Scotland) or the Scotland's People Centre (or both)?
Here are some tips for the Historical Search Room:
If you don't already have one, you will need a reader's ticket. To be issued with one you will be asked for ID which must include at least one form of photographic ID. When you order the documents you can tell them what ID you plan to bring to make sure that it will be sufficient for their purposes. The reader's ticket is free if you bring passport photos with you (you will need two) but they can take the photo for you for just £2.
If you wish to see anything which is held outside the building I would recommend ordering them well in advance (about 4 days) and phoning the day before to make sure they have actually come in. The number of times I order say 10 items and only 9 arrive is ridiculous! I'm OK because I go most weeks but if not it's really annoying.
If you're not sure where the items are kept phone and ask. You cannot get items from another building on the day you order them.
Take a digital camera! You will be allowed to photograph most documents on request, and this really speeds up the volume of material you can cover in one day and keeps costs low. Ask the staff for permission before you use your camera though.
Take a pound coin for the locker. No bags can be taken into the historic search room. The same goes for food, drink and pens etc.
Many documents can now be viewed on search room PCs on what they call the 'Virtual Volumes' system. On these PCs too is access to the sasine records, wills and Valuation Rolls. These systems are not the most user-friendly in a number of respects. Don't worry, it's not you, just ask for help if you need it.
Emma