You can use Cisco pcmcia card with laptop as minimum option, but with limited visibility and type of info can be gathered.
There's a 3rd-party product called AirMagnet where it can be used for planning, management and troubleshooting. For site survey, it provides you with various options/info such as noise level, radio channel detection (for existing AP around the area), signal strength, and many more. Personally, I think it's very useful (3-in-1 functions).
It comes in handy format - laptop and handheld. I've used the laptop format where you need to buy the software and the proprietry PCMCIA card (use your own laptop). But you need to register the software online as it need to verify/register your laptop and the pcmcia card.
For handlheld device, you have to but it as a complete package.
We have been using Ekahau Site Survey and it has been a very valuable tool that saves a lot of time.
We run the software on a tablet PC where we load in the building floorplan and easily tap on the screen to indicate our location on the floorplan. Ekahau does the rest. By walking at the same rate of speed and a straight line between tapped location points, Ekahau will interpolate the readings between points and create full-color RF readings. When you are done, you can generate beautiful HTML reports on CD for your own use or that of your customers.
For Wireless Site Survey Kit, first,you have to start with either AirMagnet or Ekahau or other softwares installed in your laptop or tablet PC. second, you need to have the access point with bracket and antennas and third, you need to have an AP mounting system that can be extended up to desired height preferably with wheels. The rolling capability will be a big help when you are going from room to room or hallways.
Your access point should be powered by a battery pack either through 48V POE for most 802.11 a/b/g or 56V for most 802.11n.
Most battery packs now can power both 48v and 56V. A camera and a dry-erase board will also help to document the location of the APs. which is vital during actual AP installation.
The next usual step is mounting the access point in a tripod to simulate the actual height of the AP for better survey result.
For site survey outdoors, bucket trucks or fork lifts are used to get to 30 ft. of height of lamp poles where the AP's are installed.
Instead of using a tripod, you can try the one that the Cisco wireless engineers are using in Milpitas, CA.
It's called WiFi Surveyor made in Chicago at www.castertray.com They have the indoor and outdoor solutions. Hope this helps.