You'll need to obtain the following items:

1. Proxim Symphony cordless networking card, model number 4100-05, or equivalent wireless network card for the 2.4 GHz frequency range.  This guide will only cover the Proxim Symphony PnP ISA card.  Adaptation to wireless network cards other than the Symphony should be trivial.  ($120 US)
2. Discarded MMDS/ITFS wireless cable parabolic dish antennas.  (free)
3. Discarded Radio Shack/Nokia transmobile cellular phone bases, or equivalent old cellular phone  (free), or an Ericsson TNC adapter, Radio Shack part number 17-341  ($5 US, clearance sale)
4. Times Microwave LMR-400 coaxial cable, or equivalent low loss 50 Ohm coax.  ($0.50 ft US)
5. Familiarity with the Linux operating system.  (priceless)
6. Various computer equipment  (486's, 10baseT cards, hubs)
7. Appropriate N plugs and N jacks for LMR-400, RG-8U, and a TNC plug to N jack adapter.  ($4 US each)
8. Steel wool, sandpaper, files, Dremel tool, flat black spray paint.
9. Waterproofing tape or sealant.  (Coax Seal, Radio Shack part number 278-1645, and 3M Super 33 or 88 tape)
10. Good topographic maps, compass, protractor and a global positioning system (GPS).
11. Various tools, mounting hardware, and quality soldering equipment.  (steal/borrow)
12. Read Jean Tourrilhes' Wireless LAN How-To end to end.

Please read this entire how-to guide to determine the number and applications for these items.