If you are going to Kew for the first time, here are a few tips to help you make the most of it. Milly is right that it can be rather bewildering (especailly ath the moment while the major refurbishments are going on.
There is a lot of useful infromation on TNA's website, in particular the Research Guides on some of the most popular subjects (nearly 300 at the last count, listed alphabeticall but you can search by key word too)
www.nationalarchives.gov.uk/catalogue/researchguidesindex.asp?j=1It is also worth clicking on the 'Visit us' tab for details about Readers' Tickets, how to get there, opening hours etc.
You can also practise using the online catalogue, which will save you time when you get there, even though you can't order documents in advance at the moment, while there is reduced capacity in the reading rooms.
While space is limited, make sure you get there as early as you can, because you may have to wait for a seat to become vacant later in the day if it is busy.
And one tip about those lovely boxes of WO97 army records. Within each box they are supposed to be in alphabetical order, and they usually are, but papers do get out of order, so if you don't find your man where he should be, look through the whole box, just in case.
Enjoy your day.
Mean_genie