Drawing up a site survey is much easier if you use a large sheet of paper, so use A3 size if possible.You don't have to use a ruler or draw it to scale as long as it is written clearly and dimensions are noted down beside the relevant item.
Start by having a good look at the room before you even being to draw. Look out for any items that could affect where shelving can go and make a mental note of any features that you think may be relevant, however insignificant they might seem - remember, the more information you give and the more accurate that information, the better our design will fit and the fewer problems will be encountered at the time of installation.
For clarity and ease of interpreting the information, it is best to use different coloured pens for different features of the room.